© copyright 2000 trevor g. hannam


ACKNOWLEDGEMENTS My deepest gratitude goes to David Tolland, who’s help was invaluable. His assistance in cutting techniques, alignment tools, transfer jigs, and gem holders has made this book a must for all faceters. To Jean Wilkinson and Ray Duncan, for their invaluable help in proof reading and correc-tion of this booklet. To Bearing Service for all the information and their help on Loctite products. Samples of the 2 tonne epoxy adhesives, and UV cement had proved to be very successful, and can be used for transferring dopped gem stones. A special thanks must go to my wife Kay, for her understanding and assistance whilst this book was being written. To present this book in the way it was to be intended, would not have eventuated without their help.

Should you wish a copy of this book Contact the Cairns Mineral and Lapidary Club Inc

129 Mulgrave Rd., Parramatta Park (P.O. Box 389W, Westcourt)

Cairns Qld 4870

Pages that are damaged through some mishap can be re-supplied @ $3.00 per page


INTRODUCTION

H ave you ever read a book that has so much technical jargon that it leaves you more confused than when you started! I think we all have fallen into this category one time or other.

It is for this reason that this book has been written. I myself found learning from such a book, if not properly illustrated or explained in everyday terms can be very frustrating and discouraging. Unless you can get an instructor to help you, most beginners will just give it up. The book and associated video (if purchased) contains detailed instructions and illustrations in concise patterns on cutting the Standard Brilliant, and gives the individual a working knowledge on the use of certain gemological instruments. Namely; Specific Gravity (Density), Dichroscope, Polariscope and Refractometer. Books and teachers of faceting often vary in their technique and most still advocate cutting the table first. Times change, and new ways are found to cutting the Standard Brilliant. This book just presents faceting another way, starting with the pavilion and as you read and learn, you will see the wisdom of this technique. There is no hard and fast rule in faceting, just the basics and beginners are encouraged to ex-periment once they have mastered the Standard Brilliant. I feel this book has presented gem faceting in such a way that any average person can learn quickly, and soon develop their own technique in the art of gem cutting. Trevor Hannam 2001


CONTENTS CHAPTER 1 Minerals Page 5 CHAPTER 2 Light and its Properties Page 8 CHAPTER 3 How to Identify Minerals Page 15 CHAPTER 4 What Machine Shall I buy Page 27 CHAPTER 5 Faceting Equipment Page 31 CHAPTER 6 Preparing Copper laps Page 36 CHAPTER 7 Selecting Rough Page 39 CHAPTER 8 The Standard Brilliant Page 41 CHAPTER 9 Dopping Page 42 CHAPTER 10 Rounding Page 44 CHAPTER 11 Cutting the Pavilion Page 47 CHAPTER 12 Polishing Page 50 CHAPTER 13 Transferring Page 55 CHAPTER 14 Cutting the Crown Page 60 CHAPTER 15 Design Your Own Gemstone Page 67 CHAPTER 16 Transposing Angles & Indexes Page 76 CHAPTER 17 Making gem stone display stands Page 77 gemstone papers & Record of Cuts Index Page 80 Bibliography Page 82 About the Author Page 82


CHAPTER 1 - MINERALS

M inerals are basically formed in primary rocks (igneous) between 600 to 1200 Degrees Celsius and have a regular atomic structure and chemical composition which is fixed

as in Quartz or varied between set limits such as Olivine. 1:1 CRYSTALS Result from any liquid which looses its liquidity, either due to evaporation which causes su-per saturation of the liquid or from temperature loss from a super saturation solution. Crystals can vary in size from just a few microns to several metres due to the slowness of drying of a supersaturated solution. All Crystals have straight and highly polished surfaces which are called Crystal Faces. Orientation and arrangement of these faces give each of these crystals a distinct form, which is only peculiar to themselves. However! Formation conditions and other chemicals may alter the crystal faces, and is known as Variation. Salt for example, would give a perfect cube, but in reality grows from a cluster due to the growth from a flat or irregular surface. Any solids which are not of a regular atomic structure are called Amorphic - Glass be-ing a prime example of this solid. 1:2 TYPES of ROCKS (a) Igneous or primary - (b) Sedimentary (c) - Metamorphic (a) Igneous rocks are normally classed as either Basaltic or Granitic. Magmas are a molten silicate material plus dissolved gasses produced by partial melting of rocks in the crust and upper mantle of the Earth. This magma is high in peridotite and rises through the mantle through small channels and crevices because of its lower density and viscosity. Vis-cosity is the way that a liquid flows. High viscosity has a low flow, whilst low viscosity has a high flow. This magma eventually penetrates the crust of the earth, and flows out onto the land as Lava. If the lava is cooled fast, fast enough so the lava does not have time to form a regular atomic structure (crystals), it will form into a volcanic glass called Obsidian (amorphic). If this lava has a high gas content (volatiles), it will produce a product we call Pumice, and was originally used as a scrubbing block and sanding material. (b) Sedimentary rocks are derived from minerals that are weathered or from new min-erals formed which are layered down to form successive beds. Over time they are compacted or cemented together. 1:3 METAMORHIC MINERALS Changed from heat and pressure to form new minerals or change older minerals. The un-usual thing that occurs here, is that the mineral undergoing the change does not melt, but un-dergoes atomic Structure Realignment. Normally the chemical composition does not change.


There are two basic types of metamorphism, (a) Contact and (b) Regional. (a) Contact metamorphism is associated with large granite intrusions where the change occurs nearest the granite. This contact of change is due mainly to heat alone with very little pressure. A good example of this, is when there is a granite intrusion into a sedimentary layer of limestone. The limestone is changed to marble. In this situation there can also be a chemical change due to permeating aqueous solutions from the granite intrusion. The car-bonates from the limestone can be replaced with aluminium and silicates to form the mineral Garnet. (b) Regional metamorphism happens on a much larger scale, and is due to both ex-treme pressure from deep burial and heat due to geothermal gradient ( 30 degree Celsius temperature increase per kilometre of burial and normal radioactivity in crustal rocks). Bending of mountains that take thousands of years cause metamorphism, and normally causes an alignment of textures which results from the deformation and re-crystallisation of the minerals without changing their chemical composition. Gneiss, being a cabbing stone for the lapidarist, starts its life as a mud shale which in turn changes to slate, to phyllite, to schist, and finally gneiss. 1:4 GEMS & HOW THEY ARE FORMED

Gems are mostly formed from hydrothermal solutions and cooling magmas Hydrothermal solutions occur along natural fissures, crevices and veins in rock. As a granite intrusion rises towards the surface it causes the upper mantle of country rock ahead to crack and split causing small to very large fissures. These immediately fill with aqueous solutions (liquid gases) under extreme heat and pressure. As they slowly cool over thou-sands of years, they form bonded layers of different mineral crystals. Some of these crystals can be enormous in size. Such as quartz. The first minerals that crystallise from the cooling solution are also the first to be weathered or broken down. This order of crystallisation of minerals is known as ‘Bowen's Reaction’. Refer Page 8 for chart Section 1:6. 1:5 ORDER OF CRYSTALLISATION -

OLIVINE Gem - Peridot

PYROXENE Gem - Augite

AMPHIBOLES Gem - Hornblende

MICA Gem - Muscovite

PLAGIOCLASE Gem - Feldspar

ORTHOCLASE Gem - Feldspar

QUARTZ Gem - Quartz


MINERAL SILICATES

Decreasing Temperature Olivine Ca - Plagioclase

Pyroxene

Amphiboles Ca - Na - Plagioclase

Mica Na - Plagioclase

Orthoclase

Mica

Quartz

1:6 Bowen’s Reaction

Notes:


CHAPTER 2 - LIGHT & ITS PROPERTIES

S peed of light Travels through air and space at 297,600 kilometres per second, but as it passes through a solid object, such as a piece of glass, it does two things. Slows down

and changes direction or bends. Why does light slow down? Because it’s passing through a denser material than air. For example, try driving a car through water. The water is more dense than the air, so we are slowed down by it. Why does light bend? As light try’s to pass through the glass it is pulled due to the sudden reduction of speed, because of the higher density. Lets take for example that we are driving on a sealed road, and up ahead there is a small amount of water on the left hand side of the road. As we come to the water and hit it at normal speed, the vehicle is immediately slowed down and pulled to the left. This is exactly what happens when light is passed through the glass. This phenomenon is known as Refraction, and is constant in all gem stones. 2:1 REFRACTIVE INDEX Is the speed of light divided by the speed of light in the mineral concerned

In Calcite Crystals and some other minerals. Light has the tendency to

split into two paths. This is known as Double Refraction.


When a gem is cut properly with angles that are designed for it, the gem will cause light to be internally reflected many times and thence returned through the table to your eyes. It is the internal reflection and refraction which produces the little explosions of colour. The facets actually acting as tiny prisms. White light breaks down readily if passed through a prism into the colours of a rain-bow. As a kid I was taught this as a name; ‘Roy G. Biv’. Meaning, Red, Orange, Yellow, Green, Blue, Indigo and Violet.

THIS PHENOMENA IS KNOWN AS DISPERSION 2:2 DOUBLE REFRACTION Light can be affected in other ways in a crystal. Minerals can either be single refractive or double refractive. In normal single refractive minerals, light behaves in its normal manner, that is, it slows down, refracts and is internally reflected. In double refractive minerals, this however is altered. Light is split up into two paths. This is due to the minerals atomic struc-ture and its having one or two axis's of different lengths.. Calcite is a very good example of double refraction. If you place a piece of clear cal-cite over some small print, you will clearly see the print doubled, as if you have gone cross eyed.


2:3 POLARISCOPE Double refractive minerals can easily be identified by using a Polariscope, which is definitely required by the amateur faceter if he or she is looking for the best optical benefits. A Polariscope consists of two discs of polarized plastic (or a cheap pair of Polar-oid sunglasses) that are separated by a mechanical support. A light source is produced underneath one of the discs. The gem rough is then placed atop of this disc, whilst your eyes are looking through the top disc. The top disc is then turned until it reaches it dark-est point. The stone is then turned or rotated in a 360 Degrees revolution in all direc-tions until you see the best position of refraction. What you see as the gem is turned is a lightness and darkness of the polarized light. Will be either 2 times for a double refrac-tive stone (known as uniaxial) or 4 times for a stone with a double axis of double refrac-tive stone (Known as biaxial). The axis of the stone or gem rough is the part where the gem turns the least amount of light and dark. Below is the principal of a Polariscope followed by the next page, a diagram that can be used for an enthusiastic amateur to build his own. This is of my own design and works very well, especially if your are out in the field and wish to identify a piece of material as being single or double refractive.

Polarized disc when 90 De-grees out of phase. Produces the darkest area. This is the correct position for viewing. The polariscope is a must for double refractive stones, such as, Zircon and Peridot.


To find the axis on your gem - rotate the top disc until it’s at its darkest point, and then turn your stone every which way you can through a 360 degree revolution between the discs until the blinking of light/dark is the least pronounced (that is where dark and light shades are at their minimum). Mark the spot and turn your stone over to the other side and repeat procedure. The line that goes through the marks is your ‘C’ axis


2:4 THE CRITICAL ANGLE As the angle of light from a source increases to the surface of a gem stone, the angle of re-fraction will also increase until a point is reached where it will run parallel with the surface of the gem stone. The angle of incidence which causes the light to become parallel to the sur-face is known as the Critical Angle. If the angle of light exceeds the critical angle, the light source will become totally re-flected. The minerals with a small critical angle will loose less light than ones that have a lar-ger critical angle. This means that gem stones with a smaller critical angle can prolong the internal reflection of light thus producing more sparkle and colour.


This gemstone has what is known as a ‘Fish eye’ effect, and is indicated by seeing straight through the centre of the gem stone producing a halo appearance around the pe-rimeter. This is caused by cutting the gem stone far to shallow, 35 Degrees.

This gem stone has been cut correctly The angles are correct for the mineral Topaz and has full total reflection which produces those little explosions of colour.

This gemstone has a dark centre and is caused by excessive leakage of light through the pavilion because it has been cut at an excessive angle of 50 Degrees.


2:5 PLEOCHROISM Certain minerals have a colour change which is caused by absorption of light when it passes through different directions in the mineral. If you turn a gem and see different colours from different directions, the mineral is re-ferred to as being Dichroic. A good example of this would be a sapphire. If looked straight down upon the crystal, that is its ‘C’ axis, the gem will appear to be blue, but if looked at 90 Degrees or side on the crystal will appear green. The gem Iolite also shows this phenomenon, but has three colour changes. Blue, clear, and yellowish. An instrument used for viewing this effect (dichroism), is called a Dichroscope, and is made from a piece of clear calcite and a lens situated in a small tube.


CHAPTER 3 HOW TO IDENTIFY MINERALS

T his chapter will help you understand how to identify minerals and gemstones. Gives you some basic understanding of using some test equipment and how a microscope (or

good eyepiece) can help in identifying a gemstone by its inclusions. Gemmology is a powerful tool in identifying minerals, but there is no need for a begin-ner or an advance faceter to have to go out and buy any of this equipment. Some equipment is very expensive, like the refractometer and is not needed for general faceting. They are helpful in trying to identify a gemstone or mineral of unknown origin. You will find the most useful tools for faceting will be the Polariscope and a small Di-chroscope to determine the correct orientation of colour in minerals suffering from pleochro-ism.

MINERAL IDENTIFICATION TABLE

ITEM DESCRIPTION ITEM DESCRIPTION

1 Colour and Streak 8 Inclusions

2 Chemical 9 Lustre

3 Cleavage 10 Magnetic

4 Density - Specific Gravity 11 Pleochroism

5 Feel and Heft 12 Refractive Index

6 Habit 13 Single/Double Refractive

7 Hardness (Moh’s) 14 Absorption of light


3:1 COLOUR & STREAK As light is passed through a mineral it will absorb certain wavelengths from the white light. The mixture of light left produces the colour we see. The colour of a gem stone is not a very good way to identify it, as variations of colour and light penetration can be deceiving. Take for instance a sheet of silica glass. When you look through it face on it appears clear, edge on it appears green, and if you crush it up into a powder it will be white. A piece of rough light blue topaz may appear just like a piece of aq-uamarine and yet they are completely different minerals. So! You can see why we cannot use colour alone for identification. Streak test of a mineral normally would be a more accurate way to determine diagnos-tic features than by colour. The mineral is rubbed against the back of a tile to produce a streak. This streak of colour produced will be constant for that mineral and is a useful tool in identifying it. A piece of hematite for instance appears to be a metallic grey with a high lus-tre. When scraped on the tile, the streak will be red. 3:2 CHEMICAL Some minerals can be diagnosed by using certain chemicals. Take a piece of calcite for in-stance (CaCO3 - Calcium Carbonate) and drop some diluted hydrochloric acid on it, and you will see it fizz and the surface of the crystal will be marred. A chemical reaction takes place and releases tiny bubbles of carbon dioxide. Calcium Carbonate comes in a variety of forms - limestone, marble, coral calcite and pearls. Pearls which consists of aragonite, another calcium carbonate will also be attacked by acids. Acid from your skin will cause deterioration of the polished surface of pearls. Peridot (Peridotites) is readily attacked by sulphuric acid and will pit its surface to the like of sand paper. This test can distinguish peridot from other minerals, such as a glass imi-tation or a piece of tourmaline. 3:3 CLEAVAGE/FRACTURE Tendency for a mineral to split in a certain direction and is constant from one sample to the next, making this a good diagnostic tool in mineral identification. The cleavage of a mineral is related to the lattice work of that crystal due to its atomic structure. Very similar to a ten-sile bolt. The bolt has extremely good strength in the lengthwise direction, but has little strength across its diameter and will shear easily. Calcite and mica crystals are very weakly bonded in one plane and will cleave easily by the hand. Cleavage is something the faceter has to be extremely aware of in some gem stones such as topaz, feldspars and spodumene. They have a perfect distinct cleavage and sudden heat, pressure or blows will induce flaws in the stone or they may just part in two.


When a mineral cleaves both faces of the plain will normally be flat and polished in appearance, however, if a piece of Quartz is broken it will fracture, and the broken piece will be bright and shiny but be rounded or circular in appearance, like the ripples on a sea shell. This fracture is classed as being conchoidal. BELOW SHOWS DIFFERENCES IN FRACTURE IN QUARTZ & TOPAZ

QUARTZ PIECES

TOPAZ PIECES


3:4 DENSITY (SPECIFIC GRAVITY) Testing a gem stone to show specific gravity is one of the main diagnostic tools in iden-tifying it. The formula for this is (X) ÷ (X) - (X - Y) = S.G. This is a very simple for-mula, where (X) is the dry weight of the gem stone and (Y) is the weight of the gem-stone weighed in demineralised water. For example; a piece of gemstone weighs 10 grams which we will call (X). This gem stone is then weighed in water suspended by a small wire hanger. This weight comes to 7.18 which we will call (Y). By using the above formula we can work out the specific gravity of this mineral. (X) 10 = 3.54 Specific Gravity. (X) - (X - Y) 10 - (10 - 7.18) This specific gravity rules out quartz (2.65), but puts it in the range of topaz 3.53 to 3.56. Fig 10 shows a sketch of a balance used for measuring specific gravity. This bal-ance was made by the author using a steel rule marked in millimetres. Each millimetre represents 1 unit of weight.


3:5 FEEL & HEFT Some minerals have a particular feel to them that distinguishes them from other minerals, such as soap stone (Steatite). A mineral that is used to make talcum powder and is used ex-tensively for carving by the lapidarist. Heft is another word that represents weight. Take for example, that you pick up a piece of clear gem stone out on the fossicking area, which hap-pens to be a piece of quartz. You gaze at it thinking that it might be topaz, but it doesn’t feel right and the heft (weight) is wrong. You would be right! The heft and feel of the stone does not match a piece of topaz because it is a piece of quartz. The density of quartz is a lot less than that of topaz, hence the heft not feeling right for that stone. 3:6 HABIT Represents the crystal shape. One specimen to the next will always be the same. Quartz will always be six sided with one face shorter or longer than the others. Habit 99% of the time will nearly always identify a mineral. 3:7 HARDNESS Friedrich Mohs, the inventor of the hardness test method shows that each mineral that is lower than the previous one can be scratched by it. A selection of 10 minerals were chosen by Mohs and then sorted out to represent a scale from 1 to 10.

The scale of hardness is a bit deceptive, in that the actual hardness of the stones between each other may be anywhere between 2 to 140+ times harder. In fact, the hardness of sap-phire compared to diamond is approx 140 times as hard, yet between Quartz and topaz it’s only approx 1.5 times. One other thing the faceter has to look for is that a lot of minerals have planes of hardness (or soft zones) which can make it difficult when cutting and/or pol-ishing the gem which can cause extreme over cutting. Borazon a man made mineral is classed as 10+ which is harder than diamond. As yet this mineral cannot be made in large quantities or size to be of use.

No. MINERAL No. MINERAL

(1) Talc (6) Feldspar

(2) Gypsum (7) Quartz

(3) Calcite (8) Topaz

(4) Fluorite (9) Corundum

(5) Apatite (10) Diamond


3:8 INCLUSIONS Inclusions in a gem stone can be a finger print to prove or disprove a mineral from be-ing a natural gem stone or a synthetic (man made) one. In general most inclusions and irregularities can easily be seen with a microscope or a good lens hand piece. Some in-clusions are characteristic to the mineral itself and often can increase the value of the gem stones. Take for example a piece of sapphire that has been subjected to an inclusive mineral, such as masses of microscopical needle crystals (acicular) to form what we know of, as star sapphire. Of course other inclusion such as cracks, cleavages, gas bubbles etc can be a pain in the but to the faceter and careful orientation of the stone has to be done to hide these under the girdle facets of the stone. These types of inclusions are often classed as flaws.

Normally one would not cut stones with flaws, unless the piece is of great value. To determine a piece of rough water worn sapphire from a synthetic stone can be difficult. A microscope or hand piece of low power can often distinguish the differ-ence by the growth lines of the mineral. Natural gem stones such as sapphire, have angular lines, whilst the syn-thetic sapphire will normally always show striated round or curved lines. Nearly all gem stones will have flaws or inclusions of some kind in them. Some are so tiny that they are nearly invisible to the naked eye, whilst others can easily be seen. Gas bubbles filled with liquid, fine rutile needles, veils of colour, striations, other crystals within the host mineral, ghost or phantom crystals caused from re-growth of the mineral and many more can be a telltale of the mineral itself.

Gas bubbles that are actually empty within the mineral will normally 95% of the time tell you that this mineral is man made. Gas bubbles do not happen in natural crystalline minerals. The only exception to this rule is volcanic glass, known as obsidian and this is not a crystalline mineral but is amorphic, a mineral that has not had enough time to form a regular atomic structure due to the mineral cooling too fast. To be able to view clearly the inclusions inside gemstones, the use of refractol will help. This imitates a polish surface closely relating to the gemstones refractive in-dex, which makes it crystal clear.


3:9 LUSTRE The sheen of a mineral - Is it earthy or dull looking, adamantine, glossy, vitreous, pearly, silky, resinous, opalescence, waxy or metallic. All these can help identify a mineral. The lustre of a mineral is determined by the way light is reflected from its surface and then to your eyes. Adamantine is classed as the highest brilliance that a mineral can have and is mostly associ-ated with diamonds, zircon, cubic zirconia and other diamond simulates. Turquoise would be classed as waxy, quartz as vitreous, Feldspar as silky and hematite as metallic. 3:10 MAGNETIC Well! Its either magnetic or its not. A piece of iron or steel will be attracted by it. The min-eral magnetite or more commonly known as load stone is natures own magnetic mineral. Also comes as an inclusion in jade, called magnetite jade and makes a wonderful cabochon. Chinese were believed to be the first people to have used load stone as a compass. 3:11 PLEOCHROISM Aquamarine, beryl, azurite, iolite, kunzite, morganite, peridot, tourmaline and zircon. The above are just a few that can be identified with pleochroism. A gem having this characteristic of two different colours when viewed from different directions is known to be dichroic or trichroic for gems with three colour. The use of a small instrument known as a Dichroscope is used to determine whether a gem stone has pleochroism or not. This instrument has a small piece of calcite (double re-fractive) inserted in one end of a tube, and a small focus lens at the other. The unit is focused on the gem stone and then the gem stone is turned around. There will be two distinct colours for dichroic minerals and three colours for trichroic. (also refer Chapter 2 section 2:5. on pleochroism). Pleochroism can be very strong to weak in a mineral and the faceter has to consider the correct orientation of the gem in order to get the best benefit of colour and dis-persion. For instance, sapphire is best cut for the blue colour and not the green.

The faceter must not confuse colour zoning with pleochroism


THE DICHROSCOPE 3:12 REFRACTIVE INDEX One of the surest methods combined with specific gravity and spectrometry to identify a spe-cific mineral. Also refer Chapter 2, 2:1. To measure this R.I. We need an instrument called a refractometer. The mineral gem has to have a level or flat polished surface, although most instrument can do polished round stones such as cabochons with the magnifier removed. The instrument has a small drop of high refractive index solution placed on the carriage and the gem stone in question is placed crown side down onto it. The lid is closed to prevent excess light from entering. When the light starts to run parallel with the surface of contact, it will cause a slight discolouration or shadow across the scale. This scale is measured in R.I, and all one has to do is read directly from the scale where this occurrence happens. Also the use of a single polariscope lens or polarized plastic placed over the sight glass and turned will give two distinct lines (double refractive) This is known as the birefringence, and can some times be so important, that it is the only measurement that can separate closely related minerals.


The use of a chromatic light (yellow sodium) is best suited for use with a refractometer, unless you are pretty rich, I suggest you use an incandescent household bulb or use a yellow filter available from the camera shops. The yellow light intensifies the edge of the R.I. line.

2:13 DOUBLE REFRACTIVE To determine whether a mineral is single or double refractive will require an instrument called a polariscope. This was pretty well describe in Chapter 2, 2:3 and is a must to anyone who is faceting. The mineral to be faceted normally will have to have its ‘C’ axis directly facing or 90º to the crown of the gem. If this is not done you will find that the gem when completed will look fuzzy or dull. This is due to the light being split into two different direc-tions (birefringence) and so requires a special orientation to be cut correctly. The main minerals a beginner will come across will be peridot and zircon. Try looking down the crown of a zircon gem and you will see the double refraction clearly. There will be a doubling of the mains.


3:14 SPECTROMETRY Or in normal terms, absorption of light. An important tool in diagnosing minerals. A good investment for the keen gemmologist. Can determine the difference between imitations, and most synthetics from natural gem stones. The spectrometer works by diagnosing the spectrum once it has passed through the gem stone. Certain wave lengths are absorbed by the gem and the spectrometer registers these wavelengths by black bands across the spectrum. Looking through the eye piece will reveal the colours of the rainbow from red to violet across the spectrometer. When light passing through the gem strikes the diffraction grate, it shows the spectrum of colours absorbed by that mineral. If using a spectrometer with a scale, it’s just a matter of reading the black bands formed against the scale. Take note though, some minerals are extremely hard or difficult to read or to see.


Diamond (Cape-Series) Diamond (type with 5040A band) Ruby Red Spinel Emerald Alexandrite Almandine Garnet Zircon Yellow Apatite

Yellow/Green Synthetic spinel

7000 6500 6000 5500 5000 4500 4000

Taken from Gemmologists’ Compendium by R. Webster, FAG - N.A.G. Press Ltd London

7000 6500 6000 5500 5000 4500 4000


Natural blue Sapphire

Demantoid Garnet

Blue & Green Tourmaline

Red & Pink Tourmaline

Yellow Chrysoberyl

Peridot

Enstatite

Yellow Spodumene

Natural Blue Spinel

Synthetic Corundum

(Alexandrite Type)

7000 6500 6000 5500 5000 4500 4000

7000 6500 6000 5500 5000 4500 4000

Taken from Gemmologists’ Compendium by R. Webster, FAG - N.A.G. Press Ltd London


CHAPTER 4

W HAT MACHINE SHALL I BUY: Nearly all faceting machines that I have come across, would do an excellent job of faceting. Today's machines compared to yester-

year are a work of wonder and will cut to precise angles with good repeatability, no matter what angle or index you have set it on. Of course the machines are only as good as the lathe that makes them. 4:1 INSPECTION So! When looking for your first Faceting Machine, you should firstly check the main post and the base assembly. These should be very robust and solid. The base should be ground absolutely flat and the main post should have no movement when it is in its fixed position. The master lap should be absolutely flat with no imperfections on the surface and defi-nitely should be easy to turn . The spindle centre should be firm and no movement should be evident. This can be checked by pushing the master lap in and out from the spindle. If move-ment is indicated, bearings may need to be replaced or in worst case scenario, replacement of the spindle. A splash pan should be able to accommodate a 6" lap comfortably and be complete with a water coolant system, though this can be added later if one is not present. Check out the Protractor to see if it is clearly marked and easily readable at the posi-tion you would normally sit. Check to see that the angle and index cheaters are variable over a small range and are not sloppy. Make sure that the index wheel is clearly marked and not damaged in any way. Normally two index wheels come with a machine, a 96 and a 64. The dop arm should be able to be easily turned in a 360 degree revolution when in free wheel, without any restrictions or hard spots and have a good locking system for the dop stick. Also check for lateral movement of the arm by slightly pulling and pushing the dop arm against the index wheel to see if there is any movement. If there is movement here you cannot expect the machine to keep the angles constant when in motion, because as you push down on your work whilst cutting, the arm could move upward or downward slightly alter-ing your cutting angle. The cutting stop (stops the dop arm from going past the protractor setting) should be solid yet variable over a small degree (known as the angle cheater). The coarse and micro height adjusters on any machine should be smooth in operation. The coarse adjuster on the post should be able to be locked in a fixed position with no noticeable movement. The Motor should either be variable speed (a definite advantage if you can procure one) or have at least 3 fixed speeds: Slow, Medium and Fast. Ask if there are any accessories that come with the machine. Normally you would expect two index gears, a set of dop sticks including a flat dop, and a good transfer jig. It would be a good idea to check the dop sticks, to make sure that they do not appear bent. Especially if they are aluminium ones. Now sit in front of the machine as if you were home to use it! Does it feel comfortable to you? Is everything in an accessible place to reach? Normally, all machines are made to be easy accessible and have all pertinent controls within arms reach when sitting down. If you think that everything is as it should be and you appear comfortable with the design of the machine, you have just taken the first step in owning your very first Faceting Machine. Have a talk to a club member or someone that has been faceting for some time and has had

the benefit of trying a few machines.


14:2 FACETING MACHINE


4:3 TERMINOLOGY 4:3.1 The Quill & Alignment Tool The quill or dop arm as it is sometimes called, houses the mounted dop stick, and is attached to the toothed gear known as the index wheel. This quill has either a self centre chuck or a small set screw to lock the dop stick in position. Some machines do not have alignment notches built into the quill, and alignment tools are essential. A good machine should have 2 or three of these. The alignment tool allows for perfect realignment, should you have to remove or replace the dop stick at any stage whilst cutting or polishing. 4:3.2 Index Wheel & Cheater The index wheel is the large toothed gear and comes in a variety of indexes. Normally the machine will come with a 64, and 96 index wheel as standard equipment. These indexes should be easily interchanged without difficulty. If not - be wary! The index wheel can be released by pushing in the arm of the spring retainer so the quill can be moved in either direction. This arm can be locked so the index wheel, and quill can free wheel for rounding. A small amount of movement, either left or right of the main setting is available by using the index cheater. The cheater will allow for small errors in cutting or polishing, and normally will have a centre mark to help you show direction (left or right) when cheating. 4:3.3 Protractor, Stop & Cheater The protractor is probably the most important part of the machine, and should have clear engraved half degree divisions with a good marker, pointer or face that can be seen, and read from nearly all directions when in normal operation. The angle stop sets the quill to any angle between 0 and 90° on the protractor, and should move freely between the stop, and the set angle. Most machines will incorporate a dial gauge or some form of indicator to give the operator a warning when the stop is reached. The stop should be solid,and held firm by a locking device so the quill cannot past this point. Located on the stop, should be the angle cheater, a small tapered shaft that can be screwed in or out to adjust the angle by the 10th degree, but be prepared, there are a lot of machines out there that do not have an angle cheater, infact most faceters will tell you that the angle cheater is not absolutely necessary. 4:3.4 The Post & Coarse Adjuster The post is the main support for the head assembly and is 90° to the base plate. The post can be either fixed or adjustable along a slide that is fixed by a locking nut. On this post, to which the head assembly is fitted, is a coarse adjuster. This is a large knurled knob which releases or tightens the head assembly to the post so the quill can be raised or lowered by hand (coarse adjustment). 4:3.5 The micro Height Adjuster Fitted to the head assembly or in some cases to the main post support. The micro height adjuster should be adjustable within a span of approximately 25mm, and is normally marked in graduated steps of 1 to 5 thou increments. Some machines do have micrometers fitted as part of their standard equipment. 4:3.6 Water Reservoir A good reserve of water should be available to the faceter. Normally all faceting machines will have a reservoir fitted to the side of the swarf tray, and have a capacity of 500 mils minimum. A stop valve should be fitted to allow control over the water flow, and the container should be able to be swung away from the lap when required.


4:3.7 Speed Control & Motor All faceting machines must be driven by an electric motor of sorts. This can be by either 240V or 12 Volt, and is normally belt driven by stepped pulleys or variable speed control. If a fixed 2 or 4 pole motor is used, then the faceting machine should be fitted with a stepped pulley system so the speed can be changed manually. A good speed for minimum is 100 rpm to 1400 rpm maximum. The best system is a variable speed system either in 240V or 12 Volt. 12 Volt is preferable due to high torque and less noise pollution. As mentioned earlier, all machines today can be considered a marvel of modern engineering. Some are better than others, and some offer more incentive by gimmicks, and attachments, but all in all, the faceter has to make the decision that suits him best. The main criteria for any faceter is Ease of Operation when facing the machine in the standard cutting mode.


CHAPTER 5 FACETING EQUIPMENT

5:1 FACETING MACHINE: - Should include dop sticks, transfer jig, 45 degree angle dop and a flat dop. It seems that quite a few faceting machine manufacturers don’t include flat dops in their kits. If you happen to be one of the unlucky ones, don’t despair, as a valve from an auto or bike shop will suffice quite well. Just be sure that it has a 1/4” or 6 mm shank. Es-sential tools, such as small spanners, screwdrivers and allen keys are a must. 5:2 LAPS: - Defined as a flat disc which is used to cut and polish gemstones. Today there is a multitude of laps offered for sale, but non better than the good old copper lap. The cop-per lap has been around for many decades, makes an excellent pre-polish lap and is still pre-ferred by many experienced faceters. These type of laps have to be charged with diamond powder, are cheap and easy to maintain. Metal bonded laps have diamond powder electroplated onto a thin copper disc which is glued to a master lap made of aluminium. These type of laps are more expensive than the copper laps, but cut flat and true with good clean facet edges. I have found from experience, that the pre-polish lap do have a tendency to become dull very quickly and therefore is not recommended for the beginner until he or she has gained more experience. Coarse laps on the other hand are a must for the faceter and will last an extremely long time and are well worth the few extra dollars to buy. Polishing laps also come in a variety of types, namely: Aluminium, brass, ceramic, Lu-cite, cast iron, tin lead, type metal, and even timber, but one can’t surpass the ever popular tin lead lap as an all round general purpose type. Used with 50,000 mesh diamond powder, it will outperform all other laps due to the metal’s ability to polish most gemstones. LAPS REQUIRED (1) Coarse 100 grit Ripple or Channel disc - Used for quick removal (2) Coarse 220 grit Copper Lap, or metal bonded type (3) Pre-polish 1200, Copper Lap (4) Polish Tin Lead lap - made from 60/40 solder All the above laps are available from any good lapidaries supplies Once you have established yourself as a faceter, try experimenting with other laps. They all work very well and you will find the aluminium lap extremely good for polishing sapphires. The ceramic lap gives clean flat sharp facet edges, and is best suited to gemstones of 8+ in hardness. Not to be considered as a general purpose lap, but if you are considering entering faceting competitions, the laps superiority over soft laps must be well considered. The cast iron lap can be considered a second best to the tin lead lap. A very good gen-eral purpose lap that can only be used with diamond powder and a good grade of olive oil. The laps coarseness or porosity of the metal makes it a good holder of polish powder. From experience, this lap can be considered to be on par with the ceramic lap, giving precise clean flat facets and is worth the while of any faceter to have one as standby for all those harder stones. The last one to mention is the Lucite lap. Made of plastic and is normally used with ce-rium or tin oxide powders mixed with water. This type of lap is generally used for polishing Quartz, and requires the lap to be kept extremely wet while in use to prevent heat build up and rounding of the facet edges. Quartz being one of the hardest minerals I have found to polish can be assisted by the use of a small amount of vinegar added to the polish mixture.


5:3 DIAMOND POWDER Diamond grit used for cutting and polishing of gems come in a variety of sizes, ranging from 0.1 to 100 micron. The diamond powder that we use today is mostly made by man, and is more consistent in particle size than natural stones which have been sieved by a screen. Grit sizes of 80 to 325 normally come in a powder form from 1 carat to 5 carat vials. Whilst 600 mesh size and over can come in a variety of containers, vials, syringes and spray packs. To start, we will need 1 carat of each size, 220 mesh, 1,200 mesh, 3,000 mesh and 50,000 mesh. The 220 mesh is the coarse grade which is used for roughing out of the mains and preforming the girdle (known as ‘ROUNDING’). The 1,200 and 3,000 mesh are both the pre-polish grade. 1,200 mesh is the all rounder for pre-polishing, whilst the 3,000 mesh is recommended for doing sapphires as they suffer badly from ‘Orange Peel’ or over cutting due to planes of softness within the mineral. The 50,000 mesh is used for the polishing stages and is a good all round polish powder. You can however use 100,000 mesh for polishing, but polishing of the facets will take a little longer. It has been my experience that there is virtually no difference between these polishing powders when it comes to viewing the finished product. 5:4 ADHESIVES 5 minute/24 hour epoxies and super glues (cyanoacrylate) are an added advantage when it comes to faceting and all faceter’s should have in their arsenal, Loctite 416 Super glue, White 2 tonne Devcon epoxy (2 hour) and a small tube of 5 minute araldite.


5:5 DOP HELP A small container of dop help which you can buy direct from any good lapidaries supplier or you can make your own. Made from shellac flakes and methylated spirits. The shellac flakes can be bought from paint suppliers or any good hardware store. Using a small glass container that has a tight fitting lid, such as a Promite container - half fill with shellac flakes and pour methylated spirits onto the top until the container is full. Shake this container vigorously for a few minutes once every day for 3 days and then let settle for a couple of days. Pour of the top part of the liquid into a small vial etc. This makes an excellent dopping media for faceters wax, inexpensive and will last you for years. 5:6 DOP STICK HOLDER A must for beginners or any enthusiasts, 3 or 4 dop stick holders. Made from a 1” broom handle. Don’t use the wife’s broom for this venture or you may very well end up in the dogs house. Cut 3 or more pieces from your broom handle approximately 30mm long and drill a 1/4” hole in the centre to a depth of around 15mm. These essential pieces of equipment will be required to hold your dop sticks in an upright position for gluing, fixing and handling your gem stones especially when using hot wax. 5:7 FACETING WAX Faceters dopping wax is made from a mixture of Shellac flakes and red Ceiling wax. Dop-ping with wax has been around since ‘God was a little boy’, and is still regarded as the all purpose adhesives for gem faceting. Normally faceting wax comes in a bundle five to six sticks per pack and is relatively cheap to purchase. 5:8 HEAD LOUPE A small head loupe of 3 1/4 power and/or a 5 to 10 power eye piece, preferably one that is corrected, so there is no distortion of the outer rim when viewing an object. A good lens that can be purchased cheaply, is an eye piece from a pair of binoculars (7X50 or 10X50). You can pick these up at second hand markets etc, and they work extremely well. 5:9 KNIFE Any small knife will be fine to use. This will have to be dedicated to the job, as the blade will be used for heating, scraping, mixing and applying adhesives. 5:10 OLIVE OIL & Polish Extender Cooking grade olive oil will do fine. This oil is used as a coating to hold and distribute the diamond powder onto your pre-polish and polish laps. When mixed with Shellite (1 part of olive oil to 40 parts Shellite), you create an excel-lent cutting oil extender for both the pre-polish and polish laps. Also, makes a very good cleaner for the laps. Pour the extender into a small spray bottle (50 Mil), as it will give a bet-ter coverage.

Beware of Naked Flames & Use Common Cense


5:11 OVEN A medium size jam tin that is cut out to suit your spirit lamp to be used as a hot plate. Used for slowly heating your gem rough to accept dopping wax to transfer onto the dop sticks 5:12 REFRACTOL Available from any good lapidaries suppliers, and is a must to the amateur faceter for seeing imperfections within a piece of rough. This oil has a refractive index close to mid range of most minerals, approximately 1.57. When this oil is applied (with a small fine artist brush) to the gem rough, it makes the surface extremely clear. Just like a piece of glass, making it easier to view inclusions. You can also purchase from a chemist some Clove and Cinnamon oil, as these have refractive indexes 1.54 and 1.62 re-spectively and will help you view gem rough that have lower and higher than 1.57. 5:13 SPIRIT LAMP Almost any type of burner or even a candle will work as a flame heater for heating wax and transferring, but you will find the alcohol lamp (as viewed above in a home made oven) will be your best bet, namely because of its a clean flame and heating ability compared to some other types. 5:14 TOOL

Making a tool for im-pregnation of diamond powder is something that you can make for your-self. Use what is left of the broom handle that you cut to make the dop stick holders. This tool is to be used for your coarse grit only and is not required for pre-polish laps. Refer to the diagram on oppo-site page to give you an idea what is required for fixing and placement of parts. You will require one bearing approxi-mately 38 X 10 X 12 mm. A small bush will have to be made for the

centre, as you will be using a 8mm bolt and nut for the axle. Some bearing companies may have small centre diameter bearings - if so, purchase one of these. Make yourself two pieces of steel plate as per diagram to accommodate the handle and bearing. Drill the right size holes for the bolt and nut and for the machine screws that go through the handle.


5:15 VERNIERS & SCALES A good pair of metric plastic vernier/callipers with dial gauge to measure gem stones, a must if you consider going into competitions. Callipers can be expensive or cheap - its best to get a good pair if possible, though I must admit in the end the pocket will decide the quality. Not essential, but advantageous is a set of scales for weighing your finished gem stones. The scales will need to be able to weigh as low as .001 carats (there is 5 carats to 1 gram).

5:16 MISCELLANEOUS 1/ - Soft tissues: The best to use here is soft Sorbent toilet rolls, and it is a good idea to fix a toilet roll holder close at hand when faceting. 2/ - Methylated Spirits and or Acetone make a good a cleaner for dop sticks and cleaning of super glues etc. 3/ - Pen and Paper: Always keep at hand to write down informa-tion when faceting. Don’t try to rely on memory, notes can always

be referred to when required. 4/ - A small 4” trim saw would be a good investment,

but can be done without as most stones can be cut directly from the rough. A small man-drel can be made by an engineer to take a

small blade on the faceting machine. This then is used to cut the mains of the stone, thus

saving the expensive laps.

NOTES:


CHAPTER 6 PREPARING YOUR COPPER LAPS

6:1 COARSE LAP We are going to roll diamond grit into the surface of one of the copper laps to form a rough cutting lap for preforming and cutting the main facets of the gemstone. Place one of the copper laps on a large flat surface such as a table, on top of several layers of news paper. Clean the lap with the polish extender that you have already made with a piece of toilet tissue. Wipe dry, and then spread a thin film of olive oil over the lap by pouring a very small amount of the oil onto a couple of folded sheets of toilet tissue and wip-ing this over the entire surface of the lap. Now spread 1 carat of 220 mesh diamond powder over the entire surface of the lap (as evenly as you can). Use your finger to help spread the powder to a uniform thickness all over, especially near the outer edges. Using the tool that you have specially made, proceed to roll the diamond mesh into the copper lap. Do not apply too much pressure at first, use full even overlapping strokes across the full surface. Turn the lap around approximately a quarter 45° and repeat the procedure. For the first


few strokes, do not apply too heavy a pressure to the diamond mesh as you will crush the diamonds. After you accomplish the first overlapping strokes, you can use a much heavier pressure. This overlapping and turning of the lap should be done for approx 30 minutes. Lis-ten as you roll, as the diamond once pushed into the copper does not make that harsh noise of grating against the roller. Scrub the lap afterwards with hot soapy water and a scrub brush. Rinse well with water and place the lap side on into your storing rack.

When laps are new they cut extremely fast be watchful for this when cutting small facets

When diamond is pushed into the cop-per, it gives because it is softer. As you work it in, the copper over-laps the grit and work hardens so the dia-mond is held in situ.


6:2 PRE-POLISH LAP Making up your pre-polish lap is very similar to the Coarse Lap that you have just done. Us-ing the other copper lap, clean the surface with a tissue with the extender fluid. Place a couple of drops of olive oil on your lap, and with a clean tissue wipe it all over the lap until it is almost dry. You will need the vial of 1200 mesh diamond powder (pre-polish pow-der). Wipe a clean finger over the lap, this will leave a smear of oil on it. Open the 1200 mesh diamond powder, place the index finger over the top and invert. Invert back again and lift the finger off the vial. You will now see a grey coating of powder on your finger. Place your finger in different spots over the lap, and then spread the powder as evenly as possible over the laps surface with your finger. The lap is now prepared, and will last a long time before the lap will need resurfacing with diamond powder.


CHAPTER 7 SELECTING THE ROUGH

A s we are a beginner, lets start with a piece of topaz. Topaz has a good relative hard-ness, has good refractive index, is nice and cheap and will produce a gemstone of spar-

kling brilliance. 7:1 CLARITY - clearness You have a piece of topaz that isn’t a piece of crystal, but has been water worn and is impos-sible to see through. Wetting this with water will help, but not enough to be able to see the inclusions and flaws etc. This is due to the refractive index (RI) of the water (1.33) not being high enough. To be able to view inside readily we need to use a liquid close to the RI of to-paz (1.63). The use of the refractol will do just that (or cinnamon oil). Paint this over the stone with an artist brush and you will be able to see right through the stone as if it were a piece of glass. Look hard into the stone, use a five or ten power eye piece and see if there are any cracks, inclusions of other minerals, cloud veils from ghost crystals or small bubbles that are probably filled with liquid. Obviously we are looking for a near flawless stone, but as nature will have it ’Nigh Impossible’. The art of faceting is for you to be able to find the flaws and hide them if they present a problem. By orientating a gem properly, flaws or inclusions can be hidden under the girdle facets. Normally though, you wouldn’t bother unless special cir-cumstances required it, like the piece of rough being regarded as a unique piece, sentimental value or having a high price. Usually the stone would be discarded for a better piece. Also refer Chapter 3 section 3:8 on inclusions. Now you have mapped out the interior of the rough for possible orientation and maxi-mum recovery of that stone. 7:2 COLOUR BANDING or colour zoning Does the stone you have selected have any colour zoning in it, or is it all colour, maybe the colour is lighter on one side than the other! Stones like ame-thyst, citrine, sap-phire and blue topaz can have one or more bands of col-our. If the colour is most important (and normally is), the rough will have to be orientated in a position so that the pavilion of the standard brilliant when cut is fully within the banding. Some care however may be needed, so that the pavilion does not protrude past this point of colour zone as the gem may loose the colour that we are looking for.


Colour banding should not be confused with pleochroism, such as in sapphires, which are double refractive. Sapphires should be orientated along the ‘C’ axis for best colour, especially corn flour blue, otherwise you may very well end up with a green sapphire. Also refer Chapter 3 section 3:11 on pleochroism. 7:3 Topaz has a cleavage plane (Chapter 3 - 3:3 page 17), which may or may not cause you a problem when polishing. If the piece you have selected is a crystal piece, or shows the cleavage plane easily, then you have no worries as orientation will easy. If your selected stone is water worn, and there is no indication of the cleavage plane, I suggest that you just go ahead and orientate the stone as if there were no cleavage. The chance of placing a stone exactly on the cleavage line is a thousand to one, and far to much emphasis has been placed on this subject. Even if you have placed the cleavage on one of the facets to be polished there will be no real problem as polishing can be done by the hand technique discussed later in the section under ‘Polishing’. So, if your piece shows the cleavage (which is 90 degrees from the ‘C’ axis), you would orientate this piece of rough approximately 5 to 6 degrees away from the axis.


CHAPTER 8 - THE STANDARD BRILLIANT

T he first faceted stones happened sometime in the late 14th and 15th century, and since that time was to be held a secret that was passed from father to son. The nineteenth

century found the art of faceting and lapidary clearly available to all amateur and hobbyists. Today, numerous books are written on the subject, and many clubs are willing to teach this art. Cutting the standard brilliant starts with a piece of rough which is rounded. Then a combina-tion of facets are placed in geometrical patterns around the stone to make use of the optical properties of that stone, thus producing a brilliance which is pleasing to the beholder. 8:1 TERMINOLOGY There are 57 facets in the standard brilliant - The crown consists of 33 facets, 8 main facets, 16 girdle facets, 8 star facets and 1 table facet, totalling approximately ⅓ of the total height of the brilliant. The pavilion consist of 24 facets, 8 main facets, 16 girdle facets, totalling ap-proximately ⅔ of the total height of the brilliant. In some circumstances the culet can be cut as a small flat facet to prevent it from fracturing and at times is considered good practice. The maximum girdle width must not exceed 5% of the total height.

STANDARD BRILLIANT TERMINOLOGY


CHAPTER 9 - DOPPING

O ne of the most important parts of faceting - Dopping must be done correctly. There’s nothing worse, especially to a beginner to have his or her gem stone full off at a crucial

point because of improper dopping. 9:1 DOP STICK SIZE Select the right dop stick for the stone, this would be approximately 50 to 60% of the size of the finished article. This will come to you with trial and error, and after a while you will be able to estimate with some accuracy the correct dop stick for the job. Once you have orientated the stone correctly as per Chapter 8, you will have to grind a small flat surface on the stone to accommodate the dop stick. This is done by placing the coarse lap (220 Grit) onto the faceting machine’s master lap. Turn the tap on the water container to the on position so a reasonable flow is running onto the centre area of the lap surface. Set the machines speed to high. Bring the stone to the surface of the spinning lap and using light pressure, proceed to cut a small flat surface for dopping. Using a piece of toilet tissue, wet it with methylated spirits and clean the ground area (don’t forget to turn off the water and the machine, leave the lap on the machine for the next phase of faceting). Paint this cleaned area with a very thin film of dop help (the one you have made). The dop help will act as a binder for the transition of wax to metal 9:2 FIXING STONE TO DOP STICK There are some stones that are quite heat sensitive, and it is best to use the modern day epox-ies, such as Devcon 2 Tonne (refer section 9:3). Leave overnight to cure for best strength. Set up the heater oven, and place the stone, painted side up onto the oven’s top. Place the spirit lamp underneath the oven and light. Gauging the right amount of heat will come to you only with experience, but as a guide line, keep lifting the stone with your fingers until you find you can no longer hold it for more than a couple of seconds, this is approximately the right temperature. Whilst the stone is warming, place your selected dop stick in one of the dop stick hold-ers you have made. Heat the end of the dop stick by placing the end into the flame. When reasonably hot bring the faceters wax into the flame with the dop stick, and melt some of the wax onto the surface to form a small ball of melted wax. During this time you may have to keep the dop stick moving around to retain the wax on the end. Continue to heat until the wax just catches fire (this is the right temperature for fixing). Immediately place the waxed end of the dop stick onto the surface of the stones painted side. Lift the combination from the oven and gently , before it cools, move the stone around until it’s in the right position. BE VERY CAREFUL HERE AS THE STONE IS QUITE WARM! - You can now see and appreciate the benefits of using dop stick holders Put the dopped stone aside to cool down and prepare your faceting machine for the next phase of your work. 9:3 USING EPOXIES - Dopping Epoxies offer the faceter a simpler alternative to that of using wax. Both epoxies and super-glues (401 Cyanoacrylate) are very reliable and have the advantage of being able to be worked at room temperatures. They also offer the faceter, superiority from premature failure due to heat build up causing the stone to shift while you are transferring from one dop to an-other and save many a burnt finger to which I can readily relate too.


Epoxies and Cyanoacrylates can be troublesome however when trying to remove the adhesive from the stone. M.E.K. thinners and or Acetone will help release most epoxies and superglues. Heat still is the best option for prying the gem stone away from the dop stick, and works very well. Using Epoxies - make sure the ground flat area on your stone has been cleaned with methylated spirits. Clean the head of your dop stick thoroughly too. You may even have to use a piece of wet and dry silicon carbide paper or similar to get it clean. Using white 2 Tonne Devcon epoxy, mix equal parts of base and hardener together. Mix extremely well, and leave for approx 2 minutes to give it some setting time. Place a small amount onto the dop stick and press onto the flat area of your stone. Set aside for at least 6 hours or overnight for best results. Super glues are not really recommended for initial stone dopping, unless a stone has fallen off the dop whilst cutting where it can easily be glued back on. I have found super-glues are far better used in transferring of dopped stones, and it is here that the adhesive works best. In summary wax has the advantage over epoxy with quick drying times as does superglues, which means you could be faceting in just a few minutes after dopping. If you can wait, then I recommend you use epoxy - it’s up to you!


CHAPTER 10 - ROUNDING

M ost teachers of faceting begin with cutting the crown first, followed by the pavilion, and has been taught this way for generations. Here we do the pavilion first, with the

crown and table facets being last. This technique allows for the amateur and professionals to be able to estimate more accurately the depth of material left for the crown, have better con-trol of placing and hiding flaws under facets, easier transferring of the pavilion to crown in the transfer jig and better control of placements of facets. The down side of this technique however is that the table facet (the last one to be cut) has to be ‘sat’ onto the star facets and meet at every point. This can be considered good practice for when you venture into the art of ‘MEET POINT FACETING’. 10:1 Setting stone to Quill - Rounding to form the ‘Girdle’ Set your index wheel of your faceting machine into free wheel, and protractor to 90°. Place your coarse lap, the one you impregnated with 200 grit diamond powder onto your master lap and do the nut up firmly (you can of course use one of the new metal bonded laps). Now place the dop stick with the dopped stone on it into the chuck of the quill. Some ma-chines, such as the Hall’s machine have specially shaped dop sticks that fit directly into the quill. If your machine does not have this facility, just place the dop ⅔ of the way into the chuck. Tighten up the chuck firmly. Lift off the gate of the swarf tray, undo the coarse height adjusting wheel to free up the head assembly and carefully lower the head so that the stone on the end of the dop stick rest lightly on the edge of the coarse lap, re-tighten coarse adjuster - refer diagram below.

Now raise the stone slightly using the micro height adjuster to lift it off the lap. Start the machine at fast speed, turn on the water at a reasonable rate so that it flows outward from the centre of the lap. Slowly lower the quill with your micro height adjuster until you hear it grinding against the lap. Rotate the gem/quill assembly slowly in an anticlockwise direction or against the rota-tion of the lap. Until you have gained experience in ‘rounding’, stick to the anticlockwise di-rection otherwise the gem may be grabbed by the lap and thrown off. Keep turning until you hear a change in the grinding. This happens as you near the bot-tom of the stop (the stop is where the cutting reaches its maximum depth, designed so that you can’t cut any further than where you had the angle set).


Lift the stone off the lap and have a look at what is happening. You will notice that some parts of the stone have been ground, and maybe some parts have not, but at this time you should be able to see some effect of the rounding. Continue the technique of lowering and grinding until it begins to look reasonably round. Al-ways stop and have a look at what is happening until you feel comfortable with what you are doing. Continue with your rounding by lowering and cutting until you hear the action of the cutting stop. Check your progress until you think its right, a small pair of plastic verniers are handy for checking out of round. Rounding is an art, and will require a bit of practice, the old saying of ‘near enough is good enough’ is not on here, and you must strive to get it perfect. Any variation, no matter how small can cause errors in you facet sizes which progressively get worse. Even the best of us have difficulties in getting it right, so don’t feel put off - PRACTICE MAKES PER-FECT If you are having difficulties with rounding, it will be because of using too much pres-sure at parts causing over cutting. To solve this problem I suggest you recut the stone in steps, that is 48 tiny facets which will be easier to see and to control. We do this by using the index gear set at 2 indexes every cut - using a 96 index wheel will produce the 48 facets needed. Leave the assembly in the same position, place your index gear on 96 and lower the quill until cutting recommences, and cut to the stop, and then go to index 2, there should be no need to lower the quill again as you now have established the depth,. Repeat for all other indexes - 4,6,8,10,12, etc until you are back at index 96. Always try and use the same pres-sure, this will alleviate the problems over cutting somewhat (pushing past the stop). When you have finished you should have 48 tiny parallel facets as shown in diagram below (this now called the ‘girdle’).

Don’t forget to turn your water off when you have finished

You have now formed the girdle of your gem stone, it was hard but we got there. Raise your

quill away from the machine, and remove the coarse lap and place it in its holder.


Now it’s a good idea to check for flaws and inclusions that you could have missed when viewing the rough. Paint a little refractol on the surface and do another check. If you see some inclusions or flaws you must try and hide them under the girdle facets, or maybe they will cut out when the pavilion is done. All this has to be decided here and now as to whether you should go on or not. Clean everything up, including your gem stone still in the quill. Cleanliness is most important during these change over of laps. Make sure you pay close attention to cleaning where your hand rests up against any part of the swarf tray. Any contamination from here on can ruin all your work let alone the laps. Next we put on the pre-polish lap (refer Chapter 6, section 6:2)

We Do Not Use Water Yet on This Newly Prepared Lap 10:2 PRE-POLISH - GIRDLE Lower the quill until it just touches the lap as before. Lift the quill from the lap and start the machine. Only use slow to moderate speed, we do not want to throw off all your diamond powder. Now! Depending whether you are doing it the’ round’ way or the faceted way for the girdle, it’s best to use very light pressure until you understand what is happening. If rounding the girdle, the index wheel will be in free wheel and should be turned against the rotation, which is normally anticlockwise. In the faceted girdle you will be starting on index 96 and progressively indexing every 2 indexes until you have completed all facets. Remember we are only trying to remove only the scratches from the last lap, and newly prepared laps cut fast. There will be no need to remove much material. When the facet/s look satiny all over the facet/s are done. If the lap seems too dry, add a couple of drops of cleaner or polish extender to it and spread with a finger. This may get a bit messy with the oil, but that’s what we have the toilet tissue for. Always clean the stone every time you need to look at it. Check to make sure you have the girdle as round as you can get it. Ok that done, lift the quill aside and put away your pre-polish lap. You may have noticed that there was no need to use water at this time, this is because the gem is being used to push diamond into the copper lap, just like when you rolled the coarse lap. Later though this wont be the case, as the diamond is pushed in, the oil forms a barrier making it more difficult to use, it’s here that the lap is washed with hot soapy water until all of the swarf is gone, and from that stage on you will be using water as the lubricant. By do-ing the lap this way, you are getting the most benefit from the pre-polish powder, and will be able to do 3, 4 or more gem stones for a measly amount of diamond powder.

Your next step is cutting the pavilion.


CHAPTER 11 - CUTTING THE PAVILION 11:1 EIGHT MAINS COMPLEX Set the new angle on the index head to 42° as this is the angle designed for the pavilion mains of the gem topaz. Reset the index to 96 if you have not done so. Place the coarse lap on the master lap (don’t forget to clean everything prior). Now you are ready to cut what is known as the ‘Eight Complex’. That’s the first 8 facets, and you have to cut them opposite to one another, this has the effect of reducing progressive error which must be avoided. Using your coarse adjuster, lower the head assembly so that the gem stone just touches the lap as before, and lock into position. Turn on the machine, water at a moderate rate and the quill by the micro height adjuster. When cutting or polishing, always use a sweeping motion across the full surface of the lap, by doing this you are preventing lap wear (forming a groove), and preventing harsh scratches and striations on the gems surface. Cut the first facet and have a look. You will notice a small facet starting to cut down towards the end of the gem stone. Lower the quill a little more and again cut to the stop. Now! Lift the quill and change the index to the complete opposite no, that is 48, and again cut this facet to the stop. So far, so good. Go ahead and cut the other six main facets in their opposite numbers - 24, 72, 60, 36 and 84. When you have done these check to see what is happening so you can familiarise your-self to what is happening. You should see the mains coming to a point (remember to always wipe your stone with a tissue when peering at the gem. Makes it easier to see and cleans up the contaminants from loose diamond powder and swarf). Continue with same sequence - lower a little, cut and look until the mains come to a perfect point. This point of the pavilion is now commonly called the culet. You have just completed the roughing in of the first major facets of the gem stone - Well Done! Now it’s time to change over to the pre-polish lap. Again lift the quill away from the lap. Put away the coarse lap and clean the machine as before. Make sure that you also clean the gem stone and quill with toilet tissue wetted with methylated spirits. It is very im-portant that this is done to prevent cross contamination from coarser grits. - The next page shows you the diagrams of the first stages of the mains complex.


Put on the pre-polish lap as before - you should be an old hand at this now. Again readjust the quill so it just touches the lap, and repeat all the procedures as be-fore. You may find when doing these larger facets that a couple more drops of extender will be required Remember that the pre-polish cuts extremely fast when new, and requires only a little pressure to achieve that satiny look. Make sure that all facets come to the exact point and that no scratches can been seen under a 25 or 40 watt lamp. - You have now completed the 8 mains of the pavilion. All the other facets on the pavilion will now be done on the pre-polish lap so it can be left on the master lap. 11:2 CUTTING GIRDLE FACETS Cutting the girdle facets are a little harder than cutting the 8 mains and require “cut a little, look a lot technique”. Set the index to 3 and the angle to 44°, this is the girdle facet angle for topaz and is normally 2° more than the mains. These girdle facets extend to about half to two thirds of the way to the culet, and meet adjoining facets in the centre on the main facet, there being sixteen (16) of them. Refer below:- Relubricate the lap with cleaner/extender and start your machine, assuming you have already made the necessary coarse adjustments for the new angle .

Again bring down the quill using the micro height adjuster until the gem stone just touches the lap. Cut a little and then have a look to see what is happening. You should start to see the beginnings of a small triangle. Now repeat this step on the index number 93. You now should have something like two (2) triangles approaching one another as shown on the diagram next page. Lower the quill a little more and repeat the exact same procedures as above. You will definitely notice the two triangles cutting higher up towards the culet and closer together at the base line. If everything is OK, just continue repeating the above until the facets meet dead centre of the mains as shown on the diagram lower right. You will also notice the height has automatically adjusted to about ½ - ⅔ way up to the culet. Now what you have just done is establish the correct adjustments for the rest of the girdle facets, so don’t alter height or any other adjustments. Again you will have to work have to work in the


the opposite indexes as you did with the mains. The next set to do will be indexes 45 - 51. Use the same procedures as before, and you then will have done another pair. From there you go on to do indexes 21 - 27, 69 - 75, and when these four pair have been done you can then go ahead and do the next four pair, but these will be easier as all that has to be done is to meet the points of the adjacent pairs. The indexes are 9 - 15, 33 - 39, 57 - 63, and 81 - 87. Congratulations! and well done, you have just

successfully cut the whole pavilion.

Take off the pre-polish lap and put it away, clean the gem stone and quill thoroughly with a tissue dampened with metho. These bits will be covered with oil, copper oxide and some diamond powder that hasn’t been rubbed in whilst cutting. While your at it clean around the swarf tray, especially paying attention to the area where your hand touches. You cannot afford to get contamination on the polish lap or you can considered it ‘Buggered’. The cost of re-lathing a lap today is not all that cheap.

NOTES:


CHAPTER 12 - POLISHING

P olishing; an art in itself - Pro’s and amateurs alike will tell you that cutting a stone is relatively easy compared to polishing, and can be considered to be the most important

part of faceting, and so it is. Unless you get it right it just won’t do. Gems that have micro-scopic scratches, grooves and lap striations (due to polishing in one spot on a turning lap) will loose a lot of brilliance. Light reflection requires a good polished surface. If light hits a good polished surface it is totally reflected, but if it strikes a poorly polished surface, light will be sent in all direction, most of which will be lost outside of the gem thus producing a gem of less brilliance that looks hazy or fuzzy, so it stands to reason that a good polish is es-sential for obtaining a gem with lots of brilliance and scintillation. You must always strive for perfection in polishing, because in the end it will definitely pay off. Today there is an arsenal of combinations that use different laps and agents for polish-ing, but non better than that of the old reliable tin lead (60/40 solder) and 50,000 diamond powder. True enough, there are times that it will not work on a gem that seems to defy all combinations, and that is where at times hand lapping can come into its own. This has saved my bacon many a time, and it is worth spending some time on it, so you too can acquire a technique of your own (discussed later).

One of the main advantages of using diamond powder compared to other combi-nations such as Linde A and tin lead is that diamond powder does not have a tendency to ‘ball’ and cause scratching on the pol-ished surface of the gem. Therefore, the lap does not have to be scored as re-quired by other combina-tions. This lap is also a dry lap as no water is used dur-ing the polishing stages and is one hell of a lot less messy, and very economi-cal to use.

IF AT FIRST YOU DONT SUCCEED - TRY, TRY AGAIN

A saying worth its weight in gold. Don’t give up, faceting is truly a wonderful hobby.


Olive oil (as used in the polish extender) is used for preparing the polish lap as diamond powder has a great affinity for oil. Polishing is done in the reverse order of cutting, that is girdle facets first followed by the mains. The reason for this is that diamond powder is an abrasive polish, and therefore cuts a little when polishing, which causes the facets to be over cut. When you come to do the girdle facets, you will notice they ride up on each other due to this over cutting, so when do-ing the main facets you will notice the facet cutting back towards the true girdle line. 12:1 PREPARING POLISH LAP Put on the tin/lead lap (polishing), and clean the surface with the extender thoroughly. Using a piece of toilet tissue, wipe the surface dry. You may notice that the lap appears greasy looking, and you would be right. That thin film of olive oil left on the lap is the base to which the diamond powder will adhere. Now’s the time to get out the 50,000 mesh diamond powder. Unscrew the top off the vial, wipe a clean finger across the lap (this will leave a small smear of oil on your finger),


place the finger on top of the vial and in-vert. Invert back again and wipe this grey powder which has adhered to your finger over the surface of the lap as thoroughly as you can. This process should theoretically polish your whole stone, but in practice doesn’t, this is mainly due to the oxides from the tin and lead fouling the lap.


12:2 POLISHING GIRDLE FACETS Set the index wheel to index 3 if you have not already done so, and leave the angle as it was (44°). Lower the quill with the coarse height adjuster as before so that it just touches the lap and tighten into place. Lift the quill aside and turn the faceting machine on to low speed. Using the micro height adjuster raise or lower the quill until you can just hear (or feel) the gem stone touch the lap, and then lift off again. Now disconnect the stop by set-ting the angle to around 25° or so. By doing this you have, relieved pressure from the angle stop so the head assembly can’t be pushed, stressed or bent out of shape by pushing past the stop when raising of the quill is required. We certainly cut to the stop, but never polish on the stop. Until you are thoroughly conversed with cutting DON’T DO IT. Put the gemstone against the lap gently, and work it across the surface for approx two seconds. Lift the quill up, clean the facet with a piece of tissue, and check to see how it’s polishing. The girdle facets depending on the size, should only take approximately 5 sec-onds to polish. Hmmm! It doesn’t look right, only the top appears to be polishing. WHAT TO DO. By lowering a very small amount with the micro height adjuster, you will be alter-ing the contact area of the polishing so that the bottom half comes into better contact. A good point to remember:

If it’s high - lower height ~~ if it’s low - increase height

Now try again for a second. Yes, that’s much better, we now have full contact of the sur-face. Never polish longer than several seconds at a time as this causes a heat build up in the gem, and may cause the stone to shift. 12:3 POLISHING & LIGHTING Now! Is that facet really polished. Can you ‘SEE’ that facet clearly. Lets look at that light you are using. You’re what? Using a 60 watt globe. No! No! No ! You may very well be ‘blinding yourself’ with the illumination. A few pointers on using lighting be-fore you go any further:

The best lighting you can use is a single 40 Watt standard clear household globe or 12 Volt 21 Candle power. Preferably with a dimmer control fit-ted. I have found by experience all the fancy lights and high wattages are a big mistake. A light that is too bright, actually masks the scratches so that you cannot see them.


What you are looking for are shadows across the scratches. Not a brilliance that nearly blinds you, and gives you severe eye strain. As you become more familiar with the lighting you will understand the logic and reasoning behind using very low wattages. Try to get the reflection of the filament on the facet, and as sure as you are reading this, the scratches if there will jump out and grab you. Always try and go for perfection when polishing and you will not be sorry afterwards Wow! The first facet is polished and completed. Congratulations, but don’t get too cocky, we've got a long way to go. Go ahead and do the rest of the facets as outlined (you do not have to do opposites when polishing, as they are already cut and set). Indexes - 3, 9, 15, 21, 27, 33, 45, 51, 57, 63, 69, 75, 81, 87 and 93. Finished! Good now reset the machine to do the main facets (that’s the eight large facets - 8 complex). Using the angle 42°, set up and start polishing as you did for the girdle facets. Don’t forget to disconnect the stop when set up is complete. We do not want to stress the quill. You will notice as you are polishing the mains, the point will cut down to the girdle line to meet as three points, and that the polishing of the facet will take longer as the facet is larger. If you find the polish is loosing its ability to work well. Go ahead and redo the polish lap as outline in section 12:1. When you have completed the pavilion, clean the gemstone, and quill with toilet tissue and meths. Depending on what type of machine you have, place the dop stick alignment tool loosely over the dop stick. Some machines and transfer blocks have special alignment grooves or tapered cuts set in them for their respective dop sticks and therefore do not re-quire the dop stick alignment tool. If you have one of these machines, take out the dop stick from the quill, and proceed with Chapter 13 - Transferring. lift the head assembly of the faceting machine up the post using the coarse height ad-juster. Remove the polish lap and put it away. Clean the machine. Adjust the angle of the protractor to 90°. Lower the head assembly down until the gem stone, and alignment tool are resting on the master lap. Make sure that the index wheel is set on index 96. While the quill and gem stone are held firmly by a finger, tighten the screws on the alignment tool, then remove dop stick from the quill with the tool attached - Refer below diagram. If you find that the gem stone is too large for the alignment tool to rest on the lap sur-face, place a bit of key steel underneath the alignment tool to lift the stone above the lap and have a parallel surface for the alignment tool to sit upon.


CHAPTER 13 - TRANSFERRING

A bove is a typical transfer jig, and is a must for transferring the pavilion of the gem stone to face about so that the crown can be cut. It is an extremely efficient and accu-

rate way to transfer from one dop stick to the other without losing alignment of facets. In faceting you must have a good transfer block. These can be checked by putting in a couple of the same size dop sticks in the holders, and bringing them together. Run a finger nail across the join, and if your nail digs in at the junction, you should have an engineer check out the alignment of the transfer block - or check the dop sticks for bending. A dop stick alignment tool is essential if the machine and transfer jig does not have any method of aligning the dop sticks.


13:1 CLEANING & PREPARING DOPS FOR TRANSFER Clean the pavilion with a little meths and toilet tissue. Brush a little dop help on the gem, and I mean a little. If you use too much dop help, it takes a long time to dry effectively, and this will cause the gem to shift due to the longer heating time required to dry it. Place the dop stick into one of the transfer blocks (normally the left hand side), and make sure that the alignment tool is positioned correctly against the transfer block so there will be no interference (refer diagram below). Select the opposite dop, which will be a cone shaped to fit the pavilion, and approxi-mately half to three quarters diameter of the gem stone. Melt a small amount of wax into the cone of the dop stick, and when cool place it in the other side of the transfer block.

13:2 TRANSFERRING the DOP STICKS Transfer dopping - the idea is to heat the dop stick (not the one with the gem stone in it), to melt the wax while slightly heating the gem stone on the other dop, yet not allowing the gem stone to get too hot to soften the wax (which will cause the gemstone to shift). When the heat is just right, you slide the heated dop stick into the other one holding the gem stone, so the wax will grab and hold. Sounds terrible! But not all that difficult once you have had a few goes. The best way to learn, would be to practice transferring a piece of rough topaz from one dop stick to the other.. OK! The real thing now - With spirit lamp lighted and flame settled, begin heating the dop stick close to the end near the wax (remember not the one with the gem stone in it). As it begins to melt. Slightly apply the heat to the gem stone whilst not losing the heat from the melted wax. As the wax starts to get very runny and catches fire, quickly press the heated dop up against the gem stone. Speed here is critical, otherwise the transfer wont succeed. If the wax is al-lowed to cool by loosing its heat, it will not grab the stone (refer diagram next page).


This may sound like you need a medical degree, or have eight hands to do the job, but it is relatively easy, and will come to you with patience and practice. Let the whole assembly cool down for ten to fifteen minutes (have a smoko break) and take out the assembly from the transfer jig by releasing and removing the pressure plates, and undoing any locking screws in the slides as above. Now test the join. The assembly must be firm, don’t use too much pressure as waxes wont take it, and as sure as God was a little boy, it will come apart. 13:2-1 Using Super Glues - (Cyanoacrylates) Loctite 401 a one-part instant adhesive made for porous, difficult to bond materials and has good gap filling abilities. High strength bonds wax to brass, alloy or steel with very fast fixing times of 5 to 30 seconds. Full cure 10 to 12 minutes. Loctite 406 is another favourite that can be used but has no gap filling abili-ties, so it is important if using 406 to get a close mated surface. Set up the gem stone as per section 13:1, but do not apply any dop help onto the gem stone. We do not want the wax to grab and hold in this application. Apply heat slowly to the coned dop stick (not the one with the gem stone) until the wax softens and begins to melt. Remove the heat and push the dop stick into the gem stone. Lock up the wing nuts and


let cool down. This will only take a couple of minutes. Loosen the wing nut holding the cone dop only and pull away from the gem stone. A small force may be required here, but will normally come away easily. You will see and im-pressed version of the gem stone into the wax. Apply a very small amount of superglue to the impression. Do not overdo the super-glue as too much will cause a weak joint. Press the dop stick hard against the gem stone and lock the wing nut. After a few minutes it is completely cured and you can now follow the next procedures, as removal etc applies to all forms of dopping. 13:2-2 TRANSFERRING WITH EPOXIES Today epoxies make life easier, as they alleviate the problems associated with melting wax shifts. Prying dop sticks apart or away from the gem stone requires the same technique used in wax transferring. The only disadvantage of using epoxies is there setting time. As with wax and super glues, epoxies use exactly the same technique, except that heat is not used for fixing of the gem stone or the dop stick. 13:3 SEPARATING DOP STICK FROM GEM STONE 13:3-1 ‘Without alignment tool’ If the machine you have has dop stick locat-ing areas built into the transfer block and quill, there will be no need to use the alignment tool, as the alignment of the dop sticks and transfer is done automatically. Sections 13:1 and 13:2 are exactly the same here, except that there is no alignment tool fitted to the dop stick. Next heat up the dop stick (Geeze! Not the one you just transferred, THE OTHER ONE), until the wax softens enough to remove. This also takes a little practice, as you are trying to heat the one side to soften the wax just enough to remove it without transferring any heat at all to the other side.

Very carefully scrape away the wax and clean the gem stone with toilet tissue mois-tened with meths. Put the transferred dop stick into the quill, and locate the alignment notch and tighten the quill nut or screw firmly. - Go to Chapter 14, Cutting the Crown. 13:3-2 ‘With alignment tool’ Set the angle of the protractor on the machine to 90°, Index to 96 if not already done so, and lock into place. The assembly complete with the alignment tool is now placed into the quill of the machine. Do not do up the nut as yet, be-cause the dop sticks have to be aligned to the lap.


Undo the coarse adjuster and lower the head assembly until the alignment tool rests on the master lap. Hold the alignment tool firmly against the master lap, and tighten the nut or screw of the quill, so that the dop stick is now held firmly into place.

The dop stick assembly is now locked in alignment with the facets, and the index 96

Lift the quill from the master lap, and remove the alignment tool, as it is no longer re-quired. Heat the outside dop stick as mentioned in 13:3-1, and remove. Clean up the gem stone carefully as mentioned earlier


CHAPTER 14 - CUTTING THE CROWN

P ut your transferred dop into the quill and lock into place if you have not already done so. Adjust the angle of the protractor to 39° (this is the angle for the crown mains), and

place the index gear onto 96. Place the coarse lap (220 grit copper lap), onto the master lap and lock into place. Ad-just the coarse height adjuster as before, to lower the quill and gem stone so that the gem stone just touches the lap, and lift off. Again we are cutting the 8 complex, but there is a difference here, as the cutting will only progress to a certain level to form what is known as the girdle facet. The girdle cannot exceed 5% of the total height of the stone. 14:1 THE GIRDLE The girdle can be round or stepped cut as previously discussed in Chapter 10, under ‘Rounding’. The girdle can be no more than 5% of the total height of the finished gem stone. Well now! You might be thinking, how the hell do I do this when all I’ve done is the round-ing and the pavilion? Good question, and it so happens that there is a simple formula for working this out. To arrive at the maximum total girdle width, multiply the diameter of the stone (this is after rounding), by .034 Lets say for example that you have a 10 mm stone after rounding. Multiply this by .034 and you have 0.34 mm. This formula gives you an approximate girdle width for a standard brilliant of 1/3 crown x 2/3 pavilion. You may have noticed, the girdle wasn’t polished. In competition it’s a must, but I for one like the frosted girdle look, it’s up to you. Polishing should be done prior to transfer-ring. 14:2 THE MAINS Switch on the machine, fast speed, and water at a moderate rate (just fast enough to keep the lap wet when turning). Start cutting the mains as before, Chapter 11, section 11:1, using a sweeping action across the lap. Keep lowering (using the micro height adjuster), and cutting until you get to approximately 5%. The reason for stopping At 5% is that you still have to

cut on the pre-polish, and this will take up approx 1 to 2% of the width, leaving you around 3%. Once you have cut this first facet to the set level, you no longer have to re-adjust the ma-chine for the other seven facets. Go ahead and proceed with the opposite index: - 48, and then 24, 72, 12, 60, 36 and 84. You may find that when you are cutting the eight main facets, that the facets may or may not reach to a point. Do not worry if the later is the case, as the star facets, and the table have yet to be done. Once the eight mains have been com-pleted, stop the machine, clean the area thor-oughly. Don’t forget the stone. Take the pre-polish lap and give it a good clean by scrubbing with detergent and water. The 1200 grit diamond powder has been pushed into the copper lap after all that cutting, and is


ready for using water only as the lubricant. Place the pre-polish lap on the master lap, and lower the quill so that the gem stone just touches the lap, lift off and start the machine (moderate speed only). You know the drill! Re-peat all the above steps for doing the mains, and pay particular attention to the facets for that satiny finish. You may also find that the pre-polish lap cuts extremely fast, so watch that you do not cut too deep. The girdle thickness has to be even alway round, otherwise progressive error will result. This may not be apparent until the girdle facets are done. OK! You have finished the crown mains. Dammed good work! You have come a long way since first putting on the stone to the dop stick. Now come those girdle facets, so lets go. 14:3 CUTTING THE CROWN GIRDLES Leave the pre-polish lap on, as this is the lap that you will use, and be cutting the girdle fac-ets. Reset the angle of the protractor to 44°. The angle for girdle facets is normally plus 5° of that of the mains. Readjust the machine height so that the gem stone just touches the lap. You should be an old hand at this now, and it will come to you automatically. Start cutting the girdle facets as you did for the pavilion. Always adjust the micro height a little bit at a time, and do not try and cut past the stop. - Remember! ‘Cut a little, look a lot’. The indexes are the same, and in opposites: 3-93, 45-51, 21-27, 69-75, 9-15, 33-39, 57-63, and 81-87. The completed gir-dles should looks as per the diagram below.


So far so good. The girdle and main facets have been done, and all we have to do now is to cut the stars in to meet the girdle facets. Change laps to the coarse one, as there may be too much material to cut for the pre-polish lap. 14:4 CUTTING THE STAR FACETS The star facets are cut at an angle of 24°. To work out this angle, take away 15° from the main facet. There are eight star facets which are cut so that they meet the apex of the girdle facets, and have a different index number compared to the mains and the girdle facets. These are: 6, 18, 30, 42, 54, 66, 78 and 90 in that order. Adjust the angle of the protractor to 24°, and set index to number 6. Set up the height as normal practice, and turn on the machine, and water. Remember the coarse lap is on so the water will need to be at a faster rate. Lower the quill so that the gem stone just touches the lap,. and cut a little, lift up, and look to see what is happening. There should be an inverted triangle or star with its apex coming down to meet the apex of the girdle facet. Caution is required when cutting down to meet other facets as we are using the coarse lap, so you must leave a small amount of mate-rial for the pre-polish to cut for the final meets, otherwise you will have to redo the whole crown as the stars would then cut into the girdle facets. When the first facet is cut close to the girdle apex, change index and do the next set. There will be no need to do opposites, as these star facets are being cut to meet an existing point.

All finished, clean the machine thoroughly, and put on the pre-polish lap. Set the quill to suit the new lap. Don’t forget! The index start is 6, and the angle stays the same. Pre-polish the star facets to meet the girdle fac-ets. Do it slowly as there is only a small amount that need to be cut. Bring the apex of the star facet down to meet the apex of the girdle facet. Good! This tech-nique is commonly known as ‘meet point’ and is good training for cutting oval brilliants. The finished stars should be as shown below.


14:5 POLISHING CROWN FACETS Set up the polish lap. Did you clean the gem stone and machine?. If not, DO IT NOW! As you have done many times before, set up the stone to the lap. The angle of the protractor does make this one a bit more difficult to set up. Just remember to adjust with the coarse, fol-lowed by the micro height adjuster to just touch the lap. Don’t forget to release the stop to prevent stress to the quill. Start the lap on low speed, and proceed to sweep a couple of times across the lap. I pre-sume that you have placed the index on 6 and not some other index. If you have not, you will notice straight away as the gem will either cut into the lap or make one horrible grating noise. No harm should be done to the facet, other than slightly rounding a facet, which you should be able to polish out. Check the facet. ‘Oh Damn! the facet isn’t polishing right’. It appears that the facet is-n’t set right. The polishing is once again showing on the right hand side and slightly down. This is how you must fix the problem. Look at the polish and determine which way the gem has to rotate to get the left hand side to polish. Yes! That’s right! - it’s has to move in towards you as you look at it. To do this turn the index cheater to the right, which brings more of the left hand side in contact with the lap surface.

Redo the facet again across the lap a couple of times and check again. You now should now see the facet is polishing towards the left hand side now, you may even have to give the cheater another little turn to the right. As you use the cheater, always turn it a small amount. OK! You now have the left over to the right, but the lower part is still not polishing. As you did once before, if you lower the height more of the bottom of the facet will come in contact with the lap. Just use the micro height adjuster and give it a nudge so the head lowers a fraction (normally anti-clockwise lowers). Try again, and yes! you have it. Once you

have this set up all The other facets can now be done in reverse order - 90, 78, 66, 54, 42, 30, and 18.

The polishing technique just discussed is at most a worse case scenario, and most times after set up there is very little cheating to be done. Now go ahead and reset the head assembly as if you were going to cut the girdle facets. Angle 44° index 93. Remember don’t forget to disconnect the stop after set up. After the girdle facets are done, go ahead and do the main crown facets. You should be an old hand at this now, and find it relatively easy. Angle 39° index 84, work in reverse order for polishing. As you were polishing you should have noticed the slight over cuts from the previous polishing now coming back to form the meets of the triangles. OK! All finished - lets clean up, place the polish lap away, and remove the gem stone/dop stick from the quill. You have virtually finished the gem stone now, and only require one more facet to do, and that is the crown table. This table is very big and I will be discussing this as another worst case scenario where you will have to use the cheater in both cutting and polishing. This now should be easy for you, and cause you no problems. Also! Lets look at the possibility that the gem stone has been accidentally cut on the cleavage plane, and will require hand polishing.


14:6 SETTING UP THE 45° ANGLE DOP Select the 45° angle dop. When set at 45° on the protractor, the gem stone is perpendicular to the lap surface (90°), which makes the crown facet parallel with the lap surface. Place the flat dop into the 45° angle dop and tighten the wing nut so the dop stick is held firm. Place the angle dop into the quill, but do not tighten the nut. Set the angle protractor to 45°, and index to 96. As the crown facet is relatively large go ahead and place the coarse lap on the master lap. Lower the assembly onto the lap as before, making sure that

the angle dop does not fall out of the quill. Lower the flat dop until it lies flat against the lap. Look side on, and check that all is flat to the surface, and while holding the flat dop lock the nut on the quill in place. Recheck for flatness and readjust using the an-gle and index cheaters if need be. The flat dop is

now parallel with the lap surface. This technique should be adopted every time you cut a stone, and must be done if cutting the crown first. This process makes the crown table facet exactly 90° to the girdle. Lift the quill, and remove the flat dop from the 45° an-

gle dop. Place the gem stone/dop stick assembly in the 45° angle dop as per page 72 and tighten. When fitting the stone into the angle dop, eye ball one of the mains facets so that it is 90° to an end of the angle dop, this will help to keep all the facets in their correct order.


14:7 CUTTING THE TABLE FACET The table facet may look difficult, but is extremely simple, and shouldn’t prove to be any problem. The facet will be cut to meet precisely eight only star/girdle facets. Set up the machine as normal so that the gem stone just touches the lap. Lift off, turn on the water and start the machine. Lower the quill and cut a little. Here you must again use the technique of ‘cut a little look a lot’, because you can’t afford to over cut this facet. The beginnings of a facet making its way to the points of the girdle star facets should be apparent. Lower the height a fraction and cut a little more - Check. When you have nearly ap-proached the meets, stop and change the lap to the pre-polish lap. Clean up as normal and set the stone to the lap as usual. Remember why this is being done? We can’t cut directly to the meets as you will cer-tainly over cut when going to the next stage. Always leave short the meets to allow for the next stage. Lower the quill to lap once again and cut a little. How much further to go! A little more, OK! Cut a little more. Remember you may be cutting past the stop so just watch that all is well here. Are all the points going to meet true? You should be well aware as you get closer to the meets. If not use the cheaters as per page 74. They must all meet simultaneously. You may cut very close to the meets with the pre-polish lap as the polish lap will remove very little of material on such a large facet. When you have finished the table the stars will be equal-lateral triangles with all the points touching the next facet alongside it.


14:8 POLISHING THE TABLE - Finished Gem Stone This facet may take a little longer to polish because of its large size

Set up the polish lap and clean the machine and gem stone. Clean the polish lap and give it a recharge as per chapter 12 section 12:1 page 54. Lower the stone and wipe across the lap and check progress of the polish. Don’t forget to release the stop when polishing. Use the index cheater and micro height adjuster to adjust facet to the surface to polish evenly. OK! Here comes that scenario I mentioned earlier. The facet does not seemed to be pol-ishing. The facet seems to be flaking with slight ripple effect. This is due to polishing on the cleavage ( not the girly type). To make the polishing work we are going to hand polish. Turn the machine off so the lap is not spinning. Wipe the gem stone across the surface of the lap by hand. Check the progress, and you will see a remarkable polish. Keep at it, and your done. It’s quite easy and you will acquire your own technique that suits you.

WELL DONE !!!!

Take the stone/dop stick out of the quill and heat the end near the gem stone so you can pry it out. Clean thoroughly with meths and tissue.


CHAPTER 15 DESIGNING YOUR OWN GEMSTONE

W here do all the hundreds of designs come from? From people like you, amateurs and professionals alike. Your faceting machine is a piece of geometrical wizardry

that places facets in precise ‘patterns’. Look at the word ‘Pattern’! There lies the answer. All gem stones when you look at them, will have facets geometrically placed, one facet on one side one facet on the other and so on. Doodle on paper with some basic patterns and change a line here and there. As you do one side do the other, and the beginnings of a new design can come about. If you are creative, check out other peoples, work and try to change a few angles here and there. Re-member this! ‘RULES ARE MADE TO BE BROKEN’ Some of the best faceters designs have come from mistakes. Always keep pa-per and pad ever present at your side. If you make a mistake in cutting, write it down, and repeat that mis-take on the opposite index or next door facet and you may very well have started your first design. All these variations, make what faceting is today.

Basically most gems faceted are variations from the standard brilliant and the Emerald Cut


PAVILION CROWN

MINERAL HARD

Moh’s Hardness R.I.

Refrative Index S.G.

Specific Gravity

Apatite 5 1.63/1.65 3.15/3.22

Beryl-(Aqua) 7.5/8 1.56/1.565 2.65/2.85

Chrysoberyl 8.5 1.74/1.749 3.68/3.78

Corundum 9 1.759/1.77 3.96/4.01

Cubic Zirconia 8 2.16

Diopside 5/6 1.67/1.70 3.20/3.32

Feldspar Labradorite 6/6.5 1.56/1.57 2.70/2.72

Garnet Almandine Australia 7.50 1.75/1.82 3.8/4.20

Garnet Pyrope Sth Africa 7.25 1.74/1.75 3.68/3.80

Iolite 7/7.5 1.53/1.54 1.54/1.55

Obsidian 5.5 1.5 2.30/2.50

Opal 5.0/6.50 1.44/1.47 1.95/2.2

Peridot 6.50/7.00 1.65/1.69 3.34

Quartz All Varieties 7 1.54/1.553 2.65/2.66

Spinel 8 1.71/1.736 3.58/3.75

Topaz 8 1.6/1.619 1.63/1.64

Tourmaline 7.00/7.50 1.63/1.65 3.00/3.15

Zircon 6.50/7.50 1.93/1.99 4.69

M

Main G

Girdle M

Main G

Girdle S

Star

43 45 39 44 24

43 45 39 44 23

42 44 38 43 23

42 44 38 43 23

41 43 34 38 19

42 44 39 44 24

44 46 42 46 27

42 44 35 39 20

42 44 39 42 24

43 45 39 44 24

44 46 42 46 27

44 46 42 46 27

42 44 39 44 24

43 45 42 46 27

42 44 39 44 24

42 44 39 44 24

42 44 39 44 24

42 44 35 39 20

Cutting Index Chart for Common Minerals

15:1 CUTTING ANGLES & SPECIFICATIONS Angles designed for each gem stone will proportionate the gem correctly


Angles are for Quartz - Proportion of gem stone best 1.5 to 1 ratio

PAVILION

(1) Angle 90° Index - 96,48,24,72 (2) Angle 63º Index - 96,48,24,72 (3) Angle 43° Index - 96,48,24,72 (4) Angle 53° Index - 96,48,24,72 (5) Angle 53° Index - 12,36,60,84 (6) Angle 63° Index - 12,36,60,84 (7) Angle 90° Index - 12,36,60,84

Cut mid way facets and corner facets with 1200 lap and polish reverse order

CROWN

(1) Angle 55° Girdle Index - 96,48, 24,72,12,36,60,84 Cut these facets to establish girdle 5% (2) Angle 42° Mains Index - 96,48,24,72,12,36,60,84 (3) Angle 27° Stars Index - 96,48,24,72,12,36,60,84

Polish in reverse order

(4) Table - use 45° angle dop and set up par-allel with lap surface. Set angle to 90°, cut and polish

15:2 EMERALD CUT

The emerald cut is basically designed for medium to dark coloured stones, or stones with a low refractive index. The depth of the gem stone will enhance lighter coloured stones, but does nothing for scintillation or brilliance. The only problem that you may encounter with cutting the Emerald Cut, is that you may find that you will have to use the index cheater often, as small amounts of pressure one side or the other of the stone will cause slight over or undercutting of facets causing un parallel facets. Adjust to get all meets so that the lines are parallel. By following the above cutting sequences, you should encounter no real problems. Cor-ner facets are cut last and are determined by the angles work out for you. Centre main fac-ets should be cut with the 1200 pre-polish lap if the stones are under 10mm or use the coarse for larger stones.


15:3 SPIDERED HEART - Step Cut 79 Facets 96 Index

Angles are for Quartz: PAVILION

(1) 63° index as marked (2) 53° index as marked (3) 43° index as marked


Angles are for Quartz: CROWN

(1) 52° index as marked (2) 42° index as marked (3) 27° index as marked


Cut and polish table last using 45° Angle dop

This type of step cut can be used for just about all shapes and sizes. Particularly suited to me-dium to dark stones, especially garnets.


15:4 ‘OLLEN’ cut - Designed by Trevor Hannam

PAVILION (1) 55° 96-12-24-36-48-60-72-84 (2) 50° 01-13-25-37-49-61-73-85 (3) 48° 01-13-25-37-49-61-73-85 (4) 44° 96-12-24-36-48-60-72-84 (5) 40° 06-18-30-42-54-66-78-90

CROWN (1) 60° 96-12-24-36-48-60-72-84 (2) 50° 95-11-23-35-47-59-71-83 (3) 45° 95-11-23-35-47-59-71-83 (4) 35° 96-12-24-36-48-60-72-84 (5) 28° 06-18-30-42-54-66-78-90

A TWIST WITH A DIFFERENCE Angles shown are for topaz - R.I. Stones of 1.6 to 1.7.

The cut produces some interesting patterns with scintillation, and does appear to suit coloured stones. Square the stone (rounding), indexing 96-12-24 etc. Follow the se-quences shown, and there should be no trouble.

*NOTE - Table is cut last


15:5 CHAMPAGNE GLASS Designed by Trevor Hannam

This design can be rounded or cut direct from rough material with no preform. Angles will suit all gems as brilliance is not the object here. Cairngorm or slight smoky quartzes give a very realistic finish to the glass - You’ll be amazed how easy it is.

CROWN Step 1 75° Indexes 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 2 40° Indexes 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 3 Polish in reverse order Step 4 Cut Table on the 45° angle dop to approximately 70-90% - 85% is good Step 5 Polish Table and then transfer - Use a medium size dop stick and put aside.

STEM A piece of quartz crystal is best used as it is basically round and long. Determine the length

required by measuring the width, and using 60% of the width for the length. The champagne stem is tapered (large end on the dop stick). Round the stem with 15% of the

total crown diameter Step 1 86° Indexing 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 2 Polish Step 3 Cut the tapered stem flat with 1200 pre-polish, using the 45° angle dop. This will accomodate the base (bottom bit) of the glass. Step 4 Transfer to a cone dop stick and put aside.

The stem is a bit tricky due to its length and small diameter - Polish carefully PAVILION - (BOWL)

Step 1 75° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 2 50° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 3 35° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 4 20° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90 Step 5 10° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90

All Facets should come to a point Step 6 Using the 45° angle dop, cut a small flat facet with the 1200 pre-polish lap to match the width of the stem. This is the largets part of the stem (15%). Step 7 Place glass and stem dops in the transfer jig, align and using 24 hour araldite or Loctite UV cement (requires UV light to set), push together and leave aside for 24 hrs. With The UV cement, leave in the sunlight for 30 minutes to set. Step 8 Remove fixture from the transfer jig and take the dopstick off the end of the stem only. Step 9 Using the 45° angle dop, cut a flat surface with the 1200 pre-polish lap

BASE Step 1 Round a stone to approximately 50% of total width using coarse lap only. Step 2 Using 45° angle dop, cut a flat table, polish and transfer Step 3 45° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90. Cut this down so the diameter is approximately 45% of total crown width Step 4 20° Indexing 90-06-12-18-24-30-36-42-48-54-60-66-72-78-84 and 90.

All Facets should come to a point Step 5 Using 45° angle dop, cut a flat on the 1200 pre-polish lap to match narrow width on the stem. Using the transfer jig, place glass and stem together, and align. Cement as above and remove from jig when set. Clean up with meths and tissue.

A REAL CRYSTAL CHAMPAGNE GLASS


Stem 60% of total height Base Large

15%

Stem Tapered to meet Base


15:6 KAYTRE CUT Designed by Trevor Hannam

Angles are for quartz 113 facets - 96 index wheel

PAVILION (1) 54° Indexing: 96-6,12-18,24-30,36-42,48-54,60-66,72-78,84-90 (2) 90° Indexing: Use the same index as No 1 (3) 47° Indexing: Use the same index as No 1 (4) 42° Indexing: 3-9,15-21,27-33,39-45,51-57,63-69,75-81,87-93 CROWN: (1) 47° Indexing: 96-12-24-36-48-60-72-84 (2) 44° Indexing: 3-9,15-21,27-33,39-45,51-57,63-69,75-81,87-93. (3) 39° Indexing: 96-12-24-36-48-60-72-84 (4) 34° Indexing: 96-12-24-36-48-60-72-84 (5) 24° Indexing: 96-12-24-36-48-60-72-84 (6) Table done last Use 45° angle dop, cut and polish

Polish In Reverse Order

You may notice that the facets (39°) on the girdle, Index 3-9,15-21, etc Are slightly raised, leaving a slight uneven girdle. If this proves a problem, cut a small t r i angular facet on indexes 6,18,30,42,54,66,78,90. Cut to even girdle and to meet with No. 3/4 Apex


15:7 KAYTRE 5 Angles are for quartz

105 facets use 96 Index Wheel

Designed by Trevor Hannam

PAVILION: (1) 49° Indexing: 3-9,15-21,27-33,39-45,51-57,63-69,75-81,87-93 (2) 90° Index as above to form the girdle (3) 43° - Index 96,6,12,18,24,30,36,42,48,54,60,66,72,78,84,90 CROWN: (1) 46° - Index 3,9,15,21,27,33,39,45,51,57,63,69,75,81,87,93 (2) 42° - Index 96,6,12,18,24,30,36,42,48,54,60,66,72,78,84,90 (3) 36° - Index 3,9,15,21,27,33,39,45,51,57,63,69,75,81,87,93 (4) 26° - Index 96,12,24,36,48,60,72,84 (5) Table using 45° angle dop - Cut and polish

POLISH IN REVERSE ORDER


CHAPTER 16 TRANSPOSING ANGLES & INDEXES

O ne of the challenges that face many amateur faceters is transposing of the facet angles from one gem to another. The task seems daunting, but is actually simple, and once

explained you’ll wonder how the hell you couldn’t see it. 16:1 TRANSPOSE ANGLES Nearly all facet diagrams will give you the angles for quartz. So! How do we transpose an-gles from quartz to topaz. ---- SIMPLE!

Crown Mains 42°, Girdle 46°, Star 27° - Pavilion Mains 43°, Girdle 45° Lets look at the Crown. Mains 42, girdle 46. OK! That is plus 4 on the Mains. Now look at the star 27, that’s -minus 15 from the mains. The pavilion mains 43, girdle 45. That’s plus 2 on the mains. Beginning to get it yet? For topaz - Pavilion mains 42° Crown mains 39° Crown girdle = plus 4° on to the mains 43° Crown stars = minus 15° from the mains 28° Pavilion girdle = plus 2° on to the mains 44°

Now we know the angles for topaz - simple isn’t it? Use this formula for all gems

16:2 TRANSPOSING INDEX Most faceters will have one or more index wheels with their faceting machine. Most common are the 64 and 96 index. This book deals with the 96 index in cutting the standard brilliant and in the faceting diagrams listed in Chapter 15. If the machine you have has a different index wheel, say a 64 index, then use the chart to transpose the correct index. The 8 mains on the 96 index is: - 96,12,24,36,48,60,72 & 84 Therefore by transposing from 96 to 64 index we will then have the f o l l o w i n g i n d e x e s : - 64,8,16,24,32,40,48, & 56 This transposition chart is for any

gemstones that use the 8 fold mains complex stones.


CHAPTER 17 MAKING GEM DISPLAY STANDS, PAPERS & RECORD of CUTS

17:1 DISPLAY STANDS Here is a good way for the amateur and professional alike to display their gem stones. A good gem display is a pleasure to behold, and is a credit to the faceter. These stands make viewing of faceted gems easy, as they can be handle with ease, with no thought of accidental dropping and touching of the facet faces with hands, causing blemishes on the gem.

Sketches illustrate the technique of making gem stone holders.

Purchase a roll of Ma-son Burnished Stainless Steel fishing wire (trace wire used in mackerel fishing) from a Ships chandlery or tackle shop. Cut a piece ap-proximately 85mm long and bend it as per part (1). The gap is around 5 to 6mm. Now bend the tips 90° as per sketch (2), about 2 to 3mm is right. Make two of these to form a set. Refer part (4), these are small brass tubes that are used in the fishing industry, and are called ‘leader sleeves’ or fer-rules. Purchase the size that suits the wire you are buying. The ferrules must be able to hold 4 pieces of wire as shown. Push the two sets of

bent wire together as per sketch, and push into the ferrule. Now! You can either solder these in or use a two pack epoxy such as 24 hour araldite. Next purchase a piece of 4mm Perspex or Acrylic Glass, and cut it into 25mm pieces (off cuts can be purchased, and are cheaper). Refer sketch (3). Round the ends with glass paper or file, and drill a small hole in the centre to accommodate the gem stone holder. The holder does an excellent job of displaying stones and can be made to suit whatever gem stone you like to cut. The prongs are rounded to prevent accidental catching of foreign bod-ies, and damaging of softer stones


17:2 GEM PAPERS Many years ago a jeweller introduced me to Diamond Papers. These papers were made of a light weight ‘Rice Paper’, and were extremely efficient for holding small stones. What are ‘Diamond Papers’? They are simply a folded piece of paper, specifically designed for holding gem stones or diamonds. Lets call them gem papers, as we are not using them for diamonds. Gem papers make excellent storage packets for categorising gems stones, and for cartage from one place to another. They prevent accidental damage to stones by reducing the risk of gem stones rubbing against one another, and are easy to make.

Mineral: __________ Wght: ____________ Colour: ___________ No. Facets: ________


RECORD of GEMS Catalogue No: MINERAL: ________________________________________ Number of facets: CUT WEIGHT: ___________ Carat COLOUR: __________________________ HARDNESS: ______________ S.G ______________ R.I. ______________ DETAILS of CUT __________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ PAVILION ANGLES: __________________________________________________ ____________________________________________________________________________________________________________________________________________________ CROWN ANGLES: _______________________________________________________ ____________________________________________________________________________________________________________________________________________________ Inclusions etc. ______________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ Dimensions of Gem & Position of Inclusions Signature: _______________________________________ Date: _____________________

17:3 Record of Gems


INDEX of SECTIONS Acknowledgements Page 2 Introduction Page 3 Contents Page 4 1:1 Crystals Page 5 1:2 Types of Rocks Page 5 1:3 Metamorphic Minerals Page 5 1:4 Gems & How They are Formed Page 6 1:5 Order of Crystallisation Page 6 1:6 Bowen’s Reaction Page 7 2:1 Refractive index Page 8 2:2 Double Refraction Page 9 2:3 Polariscope Page 10 2:4 The Critical Angle Page 12 2:5 Pleochroism Page 14 3:1 Colour & Streak Page 16 3:2 Chemical Page 16 3:3 Cleavage/Fracture Page 16 3:4 Specific Gravity Page 18 3:51 Feel & Heft Page 19 3:6 Habit Page 19 3:7 Hardness Page 19 3:8 Inclusions Page 20 3:9 Lustre Page 21 3:10 Magnetic Page 21 3:11 Pleochroism Page 21 3:12 Refractive Index Page 22 3:13 Double Refractive Page 23 3:14 Spectrometry Page 24 4:1 Inspection Faceting Machine Page 27 14:2 Faceting Machine Page 28 4:3.1 The Quill & Alignment Tool Page 29 4:3.2 Index Wheel & Cheater Page 29 4:3.3 Protractor, Stop & Cheater Page 29 4:3.4 The Post & Coarse Adjuster Page 29 4:3.5 The Micro Height Adjuster Page 29 4:3.6 Water Reservoir Page 29 4:3.7 Speed Control & Motor Page 29 5:1 Faceting Machine Page 31 5:2 Laps Page 31 5:3 Diamond Powder Page 32 5:4 Adhesives Page 32 5:5 Dop Help Page 33 5:6 Dop Stick Holder Page 33 5:7 Faceting Wax Page 33 5:8 Head Loupe Page 33 5:9 Knife Page 33


5:10 Olive Oil Page 33 5:11 Oven Page 34 5:12 Refractol Page 34 5:13 Spirit Lamp Page 34 5:14 Tools Page 34 5:15 Verniers & Scales Page 35 5:16 Miscellaneous Page 35 6:1 Coarse Lap Page 36 6:2 Pre-polish Lap Page 38 7:1 Clarity of Gem Stones Page 39 7:2 Colour Banding Page 39 7:3 Topaz Cleavage Page 40 8:1 Terminology Standard Brilliant Page 41 8:2 Cutting Angles & Specifications Page 42 9:1 Dop Stick Size Page 42 9:2 Fixing Stone to Dop Stick Page 42 9:3 Using Epoxies Page 42 10:1 Setting Stone to Quill/Rounding Page 44 10:2 Pre-Polish Girdle Page 46 11:1 Cutting the Pavilion Page 47 11:2 Cutting Girdle Facets Pavilion Page 48 12:1 Preparing Polish Laps Page 51 12:2 Polishing Girdle facets Page 53 12:3 Polishing & Lighting Page 53 13:1 Cleaning & Preparing dops for Transfer Page 56 13:2 Transferring the Dop Stick Page 56 13:2-1 Using Super Glues Page 57 13:2-2 Transferring with Epoxies Page 58 13:3 separating Dop Stick from Gem Stone Page 58 13:3.1 Without Alignment Tool Page 58 13:3.2 With Alignment Tool Page 58 14:1 The Girdle Page 60 14:2 The Mains Page 60 14:3 Cutting the Crown Girdles Page 61 14:4 Cutting the Star Facets Page 62 14:5 Polishing Crown facets Page 63 14:6 Setting up the 45° Angle Dop Page 64 14:7 Cutting the Table Facet Page 65 14:8 Polishing the Table Page 66 15:1 Cutting Angles & Specifications Page 68 15:2 Cutting the Emerald Cut Page 69 15:3 Cutting the Spidered Heart cut Page 70 15:4 Cutting the Ollen Cut Page 71 15:5 Cutting the Champagne Glass Page 72 15:6 Cutting the Kaytre Cut Page 74 15:7 Cutting the Kaytre 5 Cut Page 75 16:1 Transposing Angles Page 76 16:2 Transposing Index Page 76 17:1 Making Display Stands Page 77 17:2 Making Gem Papers Page 78 17:3 Records of Cuts Page 79 Bibliography Page 80


BIBLIOGRAPHY Diagrams for Faceting Volume 1 - Glenn & Martha Vargas Diagrams for Faceting Volume 2 - Glenn & Martha Vargas Diagrams for Faceting Volume 3 - Glenn & Martha Vargas Description of Gem materials (third addition) By Glenn & Martha Vargas Faceting for Amateurs (second edition, revised) By Glenn & Martha Vargas “GEMSTONES of the world” by Walter Schumann - 1984 Sterling Publishing Co., Inc., New York 10016, and N.A.G. Press, Ipswich Suffolk 1977 “Guide to AUSTRALIAN MINERALS” by John A. Talent – 1970 “GEMS and PRECIOUS STONES” by Simon & Schuster’s Edited by Kennie Lyman “The Book of Gem Cuts” Volume 1, 2 and 3. By M.D.R. Manufacturing Co., Inc. 3517 Schaefer St., Culver City, California 90230 - 1971 “The GEMMOLOGISTS’ COMPENDIUM” by Robert Webster, F.G.A. Fifth Edition 1975 “THE JEWELRY REPAIR MANUAL” by R. Allen Hardy Second Edition 1986 “The Techniques of MASTER FACETING” by Gerald L. Wykoff, G.G. 1985 - Adamas Publishers, P.O. Box 5504, Washington D.C. 20016

Trevor G. Hannam, born in Wudinna South Australia, moved to Cairns Queensland 1966. Introduced to faceting by Kay & Jimmy Gadd,

where he learned to facet with the help of Bob Johnson. Furthered the study of gems by com-pleting a diploma in ‘Earth Science’, and con-tinued to study the art of ‘Gemmology’ through kye Jewelers. Working for Sharplift Pty., Ltd., in Cairns he currently manages the design, manufacturing and sales of desalination equipment world wide.

ABOUT the

AUTHOR

© copyright 2000 trevor g. hannam

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