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Mineral s. What is a mineral?. Solid Not a liquid or gas Naturally Occurring Found in nature , not man-made Inorganic Is not alive and never was , non-living Fixed composition
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What is a mineral? • Solid • Not a liquid or gas • Naturally Occurring • Found in nature, not man-made • Inorganic • Is not alive and never was, non-living • Fixed composition • Has a chemical formula, most are formed from compounds of two or more elements, some minerals consist of one element ex. Au, FeS • Crystal Form • A 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? The next few slides show an assortment of items. As a group, categorize the items as either: MineralsorNon-Minerals.
Please make this chart below • Minerals • Non-Minerals
And the answers are… • Minerals • Gold • Topaz • Quartz • Talc • Iceberg • Diamonds • Non-Minerals • Wood - once living • Fossils – once living • Bone - living material • Granite - intrusive igneous rock • Pearls – made by oysters • Coal - Sedimentary rock • 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. PYRITE GOLD CHALCOPYRITE
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 whichatomsarearranged to form a materialwitha crystal structure
Two ways that minerals form? • Crystallization of magma and lava • 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