Minerals•A mineral:

–occurs naturally–Is inorganic–Is solid–Has a crystal structure–Has a definite chemical composition

Minerals• There are 3000 minerals.

• 100 are common.

• 20 minerals make up most of the rock’s of Earth’s crust (rock-forming minerals).

Mineral Formation• Minerals form through:

•Crystallization of melted materials.

•Crystallization of materials dissolved in water.

Crystals• Repeating

patterns of a mineral’s particles that form a solid.

Minerals• All minerals contain certain

elements in definite amounts.• Most minerals are compounds

(two or more elements).• Silver and gold are considered

minerals.

Mohs Hardness Scale

The Mohs hardness scale ranks ten minerals from softest to hardest.

Talc 11Gypsum 2Calcite 33Fluorite 4Apatite 55Feldspar 6Quartz 7Topaz 8Sapphire 99DiamondDiamond 10

Minerals are ranked according to:

•Color

•Streak– the color of a mineral’s powder.

•Luster – how shiny a mineral is.

•Density—mass per unit

volume (specific gravity)

•Cleavage – breaking of a mineral along a regular line.

•Fracture – irregular breaking of a mineral.

Fluorescence

Minerals that glow under ultraviolet light.

Magnetism

Magnetism occurs naturally in some minerals, such as magnetite.