Download - Mineral s
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?
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
What properties identify minerals?
• Color• Streak • Luster • Density• Hardness• Crystal System • Cleavage and fracture• Special Properties
What properties identify minerals?
• Color – a physical property – Often not enough info.
GOLD
CHALCOPYRITE
PYRITE
What properties identify minerals?
• 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.
What properties identify minerals?
• Luster – describes how light is reflected from a mineral’s surface.–Metallic, Sub Metallic,
Glassy, Silky, Waxy/Greasy, Earthy
What properties identify minerals?
• Density – mass per volume – Can compare by picking
up like sized pieces
What properties identify minerals?
• 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 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
Two ways that minerals form?
• 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
Two ways that minerals form?
• 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.
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
Describe the processes used to get minerals.
• 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.
Describe the processes used to get minerals.
• 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