JADE (JADEITE, NEPHRITE) DEPOSITS

Jade is the gem name for mineral aggregates

composed of either or both of two different

minerals, Jadeite and Nephrite. Jadeite is a

sodium-rich aluminous pyroxene; nephrite is a

fine-grained, calcium-rich, magnesium, iron,

aluminous amphibole. All jade is composed of fine-

grained, highly intergrown, interlocking crystals of

one or both of these minerals. Though neither

mineral is very hard (6-7), jade is one of the

toughest gem minerals known because of the

intergrown nature of the individual crystals.

Most jade on the market is composed of nephrite; jadeite

jade is quite rare and in its emerald-green, translucent

form is referred to as Imperial Jade or "gem jade". A

small amount of Cr in jadeite accounts for the color of

imperial jade. Other color-based names for jadeite jade

are Yunan Jade, for a uniquely appearing dark green,

semitranslucent jade, Apple Jade for apple (yellowish

green) green jade, and Moss-in-Snow for white jade with

v i v i d g r e e n s p o t s a n d s t r e a k s.

Nephrite and jadeite jade ranges in color from a

somewhat greasy-appearing, white ("mutton fat jade") to

dark and light shades of green, gray, blue-green,

lavender, yellow, orange, brown, reddish-brown, and

black. An important dark green variety of nephrite is

sometimes known as "spinach jade". The chromophore

in all nephrite jades is usually Fe. Nephrite jade is

The name jade has been, and continues to be,

applied to a variety of materials that superficially or

closely resemble jade but are not composed of

either jadeite or nephrite. Some of the problem can

undoubtedly be traced to cultural and historical

differences in word usage. In China, for example, the

word jade has traditionally been applied not only to

nephrite and jadeite jade, but to green serpentine

and soapstone (talc) whose appearance closely

resemble true jade. Common misnomers and the

materials they represent are: "Korean" Jade for

serpentine or gem serpentine (bowenite), "Indian"

Jade for aventurine, "Mexican Jade" for green-dyed

calcite, "Transvaal Jade" for green hydrogrossular

garnet, "Amazon or Colorado Jade" for amazonite

(blue-green or green) feldspar and "Oregon or Swiss

Jadeite is a mineral that is restricted in occurrence

to certain metamorphic rocks that have undergone

metamorphism at high pressures but relatively low

temperatures. Jadeite jade is found exclusively as

nodular or lens-shaped masses in serpentinite.

Nephrite jade , which is also a product of

metamorphism (and fluid infiltration), does not

apparently require the very special P-T conditions of

jadeite and is much more widespread. It is also

found in association with serpentinite in all known

localities. Because of its extreme toughness in

contrast to the weaker material i t forms in

(serpentine), jade is nearly always found as

weathered boulders and cobbles in stream deposits

o r g l a c i a l s e d i m e n t.

Historically and presently important jade producing

localities are:Burma, near Tawmaw and Hpakon

Turkestan (central Asia between Iran and Siberia)

Canada, British Columbia Southern Frazier River

drainage,

USA.,Wyoming, near Lander; since 1936 , Alaska,

in Kobuk

River Watershed at Jade Mountain

New Zealand, South Island

Others: Poland (white nephrite); Taiwan; Monterey

Co.,

California (poor quality jadeite); Guatemala

(green

While jadeite is mined today primarily in Myanmar,

small quantities can be found in Guatemala.

Although neolithic jadeite axes were found in

Europe, it is not known where this prehistoric jadeite

was mined, although it is possible that the material

c a m e f r o m a d e p o s i t i n t h e A l p s.

Nephrite is mined in Canada, Australia, the United

S t a t e s , a n d T a i w a n.

http://www.highestoffer.com/jade.html

The Emerald Buddha, the sacred image that is

enshrined at Wat Phra Kaeo in Bangkok, Thailand,

was carved from a solid block of beautiful green

j a d e i t e.http://www.escati.com/emerald_buddha.htm

The ancient jade carved in China was what we today

cal l nephrite jade: an amphibol i te minera l .

(Interestingly enough, the word nephrite comes from

the Greek word for kidney, nephros, a bit more

scholarly version of the same thing.) In the 19th

Century , it was discovered that the material from the

new world was not the same mineral as the jade from

China. The mineral from Central America, a pyroxene,

was called jadeite to distinguish it from the The

Chinese knew about jadeite, travelers had brought

back some jadeite from Burma as early as the

thirteenth century. But China was turning inward at

that time and this foreign Kingfisher Stone, as they

called it, referring to the brightly colored feathers of

the bird, was not considered to be real jade. It only

became popular in the eighteenth and nineteenth

http://www.highestoffer.com/jade.html

Although nephrite jade is

China’s original “Stone of

Heaven,” fine jadeite, as in

this matched pair of semi-

transparent bangles (53.4

mm in interior diameter,

9.8 mm thick), is the most

sought-after of jades in the

Chinese community today.

http://www.palagems.com/

burma_jade.htm

Map of Upper Burma showing

the jade mines in the far north.

Maw-sit-sit is mined in the

v i c i n i t y o f H p a k a n.

(Courtesy of Richard Hughes)

JADE AND MAW-SIT-SIT OF

MYANMAR

JADEITE

variety Imperial Jade

Na(Al,Fe)Si2O6

Tawmaw, Myanmar

Translucent bright green jadeite, called imperial jade, is

among the most highly prized of all jades. Jade is an

excellent material for carving because of its extreme

t o u g h n e s s.

Size / Weight: 42x22x3 mm / 25.11 carats

http://www.nhm.org/research/minsci/

Portions of this article originally appeared in Gems &

Gemology, Vol. 36, No. 1, pp. 2–26.

http://www.palagems.com/burma_jade.htm

A “cousin” to jade, maw-sit-sit isan attractive ornamental stone thatis an intergrowth mainly of albite,clinochlore, kosmochlor, chromianjadei te , and eckermanni t icamphibole. These two maw-sit-sitcabochons weigh 9.87 ct (oval)a n d 8.48 c t.

An uncut jade cobble of Burma.

G e m o l o g y

Maw-sit-sit may be distinguished

from jadeite and nephrite by its

appearance as well as its physical

and optical properties. It has a

refractive index that ranges from

1.52 (most common) to 1.74 (least

common) depen d ing on the

aggregate mineral composition. The

density is therefore also somewhat

variable, falling between 2.5–

3.5g/cm3. Most cutters agree that

the hardness falls between 6 and 7

on the Mohs’ hardness scale.

Rough and cut maw-sit-sit

Dr. Vince Manson, of the GIA, first suggested in 1979

(based on unpublished data) that maw-sit-sit might contain

ureyite, which is a sodium chromium pyroxene

(NaCrSi206) where chromium (Cr) replaces aluminum (Al)

in the chemical composition. Ureyite, which was named in

honor of Professor H.C. Urey, is today properly termed

kosmochlore. The name kosmochlore (green from outer

space) is derived from the fact that it was originally found

only in meteorites. Dr. Henri Hanni, of the SSEF, in Basel

Switzerland, noted in 1986 (based on unpublished data)

that maw-sit-sit is composed of six main components.

They are as follows: chromite, ureyite, chrome-jadeite,

symplektite, chrome amphibole, and a matrix of lighter

m i n e r a l s.

M A W - S I T - S I T : G e o l o g y & m i n i n g

Maw-sit-sit is an aggregate of numerous minerals found in

the famous jade mining region of Tawmaw in the

Himalayan foothills of northwestern Burma. This small

mining area lies approximately half a mile northwest of

the village of Namshamaw. The maw-sit-sit mining area

is found in part of what is known as the Namshamaw

dike. Maw-sit-sit, like the jadeite found in this region was

formed due to high pressure regional metamorphism. This

region lies on a plateau at an elevation of approximately

3000 feet within the Uru river drainage basin.

Maw-sit-sit is a byproduct of jadeite mining and is

quite rare in comparison to jade. The mining

techniques used today are similar to those

employed three decades ago when Dr. Gubelin

first stumbled upon the unique gem material, with

the exception of modern machinery used to

excavate and tunnel through the thick overburden.

Production has increased recently with demand,

however, fine quality maw-sit-sit remains difficult

t o a c q u i r e.

There are actually two types of maw-sit-sit being

found:

• Maw-sit-sit – the rich green hue with a

medium tone containing contrasting black streaks

or spots.

• Kyet Tayoe – the lighter apple green hue with a

fainter tone containing little or no black streaks or

spots.

Of the two, maw-sit-sit is certainly more

attractive. Until demand increases, it will be

difficult to determine the potential supply but thus

far it seems to still be quite a rare occurrence.

Sketch map

of Upper

Burma,

showing

the route to

the jade

mines at

Hpakan.

Routes into Hpakan are virtually impassable during the

rainy season.

At the Ka Htan West mine,

located between Lonkin and

Tawmaw, large peridotite

boulders can be seen at the

base of this 15-m-high wall of

Uru Boulder Conglomerate.

In some areas at Tawmaw,

miners must dig deep shafts

through the overburden to

reach the jadeite dikes. Dirt

and gravel are removed by

a rudimentary winch-and-

b u c k e t s y s t e m.

Once a dike is exposed at Tawmaw, jackhammers are needed

to break the jadeite apart.

Mining of the Uru conglomerate is done in step-like claims approximately 5 m wide that were originally separated by thin “walls.”

At Mamon and Maw-sisa inparticular, miners takeadvantage of the seasonswhen the river is high todive for jade. While a manon land or a raft works thecrude air pump (whichresembles four bicyclepumps strapped together),this diver at Maw-sisasearches the river bottomfor jade with the hosebetween his teeth (inset).

At Nansibon, backhoes are

used to work the serpentinite

boulder conglomerate in

which jadeite boulders occur

i n n a r r o w h o r i z o n t a l

c o n c e n t r a t i o n s.

Thousands of workers removethe dirt and gravel at Hpakangyito reach the Uru Conglomerateand its promise of fine jadeite.Using the most rudimentary ofcarrying devices – two crudelyfashioned bamboo buckets –this young miner leads a trail oflaborers up the steep path fromthe bottom of the pit to a truckthat will carry the waste to ther i v e r.

The color of luck

Miner with jade at the Uru

River tailings dump in the

center of Hpakan.

Top centre: This jadeite boulder shows the relatively thin skin andpotentially good color that is usually associated with “river jade.” Althoughfrom the outside this appears to be a normal jadeite boulder, oxidants thatentered through cracks on the surface have produced a large area ofdiscoloration. Bottom left: Note the thick yellow “mist” around the jadeitein this boulder of “mountain jade.” Right: A key advantage to jadeitetaken from in situ deposits is that the quality of the material is readilya p p a r e n t.

The color of money

Examining jadeite in

Hpakan.

Leaving Las Vegas

A room with a view

U Tin Ngwe, who went

from taxi driver to jade

k i n g p i n a l m o s t

overnight, stands atop a

small fortune of jade at

h i s H p a k a n h o m e.

In Mandalay, cutters still

use a board coated with a

mixture of carborundum

(of various grits) and hard

wax to shape cabochons.

They then polish jadeite

on bamboo lathes, often

without any abras ive

The Golden Hand

To get a better idea

of the quality of

color in this boulder,

the dealer places a

metal plate at the far

side of a small area

with potential and

then uses a penlight

to i l luminate i t..

“Windows” cut into

t h i s o t h e r w i s e

u n d i s t i n g u i s h e d

b o u l d e r f r o m t h e

Burma Jade Tract

reveal the presence of

a rich green in the

jadeite beneath the

skin. Boulders such as

this are the source of

the fine green, orange-

red , and lavender

cabochons that are

much sought-after in

China and elsewhere.

In sawing jadeite boulders, center saw cuts (left) run the risk of cutting through avaluable area. A better method (right) involves making shallow saw cuts from oneend (perhaps the thickness of a bangle, so that each slice can be used forbangles/cabs) until one hits good color. Then the process is repeated from theopposite end, again until good color is encountered. This defines the region of top-grade material. The process is repeated until the area of best color is isolated. Thesecross-sections also illustrate a show point and an oxidation stain penetrating thej a d e i t e t h r o u g h a c r a c k.

Vendors workthe morningjadeite marketin Mandalay.

Foreign buyers examine rough jadeite at the 1992 gem emporium at

Rangoon’s Inya Lake Hotel. Such emporiums were once the only legal

way to do business in Burma, but today trading is possible via licensed

p r i v a t e g e m d e a l e r s.