MineralsMinerals

The world beneath usThe world beneath us

Exactly What are Minerals?Exactly What are Minerals?

• Minerals are naturally occurring solids with an orderly arrangement of atoms

Why are they important?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?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 ExamplesOre Examples

Bauxite - aluminum

Hematite - iron Ilmenite – titanium

How are they classified?How are they classified?

• Scientists classify minerals according to:– Hardness– Luster– Streak– Cleavage and Fracture

Hardness of Common Objects

Fingernail

Copper Penny

Iron Nail

Glass

Steel File

Streak Plate

Testing HardnessTesting Hardness

HardnessHardness

• 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.

LusterLuster• Is the way a mineral reflects light. A

mineral can be identified as:

– Dull

– Pearly – Silky

– Glassy

StreakStreak

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

Cleavage and FractureCleavage 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

CleavageCleavage

• Think of the layers in a cake

Mica