Minerals The world beneath us

Exactly What are Minerals? Minerals are naturally occurring solids with an orderly arrangement of atoms

Why are they important? Minerals can be mined for precious jewels or to make objects we use everyday Gems are highly prized minerals that are clearer and more colorful than common samples of that mineral.

Why are they important? Other minerals are ores from which elements like aluminum, iron, and titanium can be processed. An ore is a mineral or rock that contains a useful substance that can be mined for profit.

Ore Examples Bauxite - aluminum Hematite - iron Ilmenite – titanium

How are they classified? Scientists classify minerals according to: Hardness Luster Streak Cleavage and Fracture

Testing Hardness Hardness of Common Objects Fingernail Copper Penny Iron Nail Glass Steel File Streak Plate

Hardness Tells how easily a mineral can be scratched. Talc is the softest mineral,and so on the Mohs scale it receives a value of one Diamonds are the hardest mineral, and so on the Mohs scale it receives a value of 10 Diamonds can only be scratched by other diamonds. They can also scratch glass.

Luster Is the way a mineral reflects light. A mineral can be identified as: Dull Pearly Silky Glassy

Streak The color of a mineral when it is in a powdered form

Cleavage and Fracture This refers to the way a mineral breaks Cleavage – when minerals break along smooth, flat surfaces Fracture – when minerals break with uneven, rough, or jagged surfaces

Cleavage Think of the layers in a cake Mica