mineral s

MineralsMinerals

What is a mineral?

SolidNot a liquid or gas

Naturally OccurringFound in nature, not man-

madeInorganic

Is not alive and never was, non-living

Fixed compositionHas a chemical formula,

most are formed from compounds of two or more elements, some minerals consist of one element ex. Au, FeS

Crystal FormA definite structure in

which atoms are arranged

Define a mineral.

• A mineral is a naturally formed, inorganic solid that has a definite crystalline structure.

How can I determine it is a mineral?

• Is it non-living material?

• Is it a solid?• Is it formed in

nature?• Does it have a

crystalline structure?

Please make this chart below

• Minerals • Non-Minerals

Fossil

Granite

Quartz

Pearls

Diamond

Rock Salt

And the answers are…• Minerals

a) Goldb) Topazc) Quartzd) Talce) Icebergf) Diamonds

• Non-Minerals

a) Wood - once livingb) Fossils – once livingc) Bone - living materiald) Granite - intrusive igneous

rock e) Pearls – made by oystersf) Coal - Sedimentary rockg) Rock Salt – Sedimentary rock

Identifying Identifying MineralsMinerals

What properties identify minerals?

• Color• Streak • Luster • Density• Hardness• Crystal System • Cleavage and fracture• Special Properties


• Color – a physical property – Often not enough info.

GOLD

CHALCOPYRITE

PYRITE


• Streak – color of its powder. – Test – drag across

porcelain tile– Often different than color

Streak plate showing magnetite with gray streak (left) and hematite with reddish-brown streak (right). Photo by M. Minitti, ASU/CMS.


• Luster – describes how light is reflected from a mineral’s surface.–Metallic, Sub Metallic,

Glassy, Silky, Waxy/Greasy, Earthy


• Density – mass per volume – Can compare by picking

up like sized pieces


• Hardness – can it scratch or is it scratched by another mineral. – Test – scratch test

• Mohs Hardness scale – Ranks 10 minerals – Talc, gypsum, calcite,

flourite, apatite, feldspar, quartz, topaz, corundum, diamond.

• What if the mineral isn’t on the list– Try scratching one that is.

HOW HOW MINERALS MINERALS

FORM?FORM?

How do minerals form?

• Crystallization – The process by which atoms are arranged to form a material with a crystal structure

Two ways that minerals form?

1. Crystallization of magma and lava

2. Crystallization of materials dissolved in water


• Magma cools inside the crust and lava cools on the surface– Both will form crystals

• Size of crystals depends on:– Rate of cooling• Slow = large crystals

– Amount of gas– Chemical composition


• Minerals dissolved in solutions

• Evaporation– When a solution with

minerals dissolved in it evaporates the crystals are left behind • Halite, Gypsum, Calcite

• Hot water solutions – Magma heats water ,

minerals dissolve, water cools and minerals crystallize.

– Metals dissolve and flow through rocks to form veins.

Uses of Uses of Minerals Minerals

Describe three uses of minerals.

• Gemstones– Rubies, sapphires

• Metals – Aluminum, iron, copper,

silver, gold

• Other – Food , Medicines,

Fertilizers, Building Materials

Describe the processes used to get minerals.

• Metals Minerals • Remove rock from

ground containing mineral.

• Process to extract mineral or Ore.

• Ore – rock that contains metal or useful mineral that can be mined and sold for profit


• Prospecting – looking for ore deposits. – Studying maps to find

where ores may occur

• Mining – removing ore from ground– Strip mines – scrape soil

to expose ore – Open pit mines – huge pit

to find ore – Shaft mines – network of

tunnels following veins of ore.


• Smelting – ore is mixed with other substances and then melted to separate useful metal or element.

• Removing impurities • May add other things to

make • Alloys – solid mixture of

two or more elements

mineral s

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