MINERALSChapter 3

What is a Mineral?

• A mineral is a naturally occurring, inorganic solid with a definite structure and composition.

• Inorganic – not alive, never was alive, and not made by life processes.

5 Characteristics of Minerals

1. All minerals are formed by natural processes.

2. Minerals are inorganic

3. Minerals are all solids

4. Every mineral is an element or compound

5. All minerals have crystals.

3 Ways Minerals Form

1. Cooling of Magma

2. Minerals are dissolved in liquids – and then are left behind when the

liquid evaporates.3. Falling out of a solution

(precipitation)

Crystal Systems

Garnet - cubicZircon - Tetragonal Quartz - Hexagonal

Sulfur - Orthorhombic Gypsum - Monoclinic Feldspar - Triclinic

Mineral IdentificationTest Description

Appearance Observe - What does it look like?

Hardness Mohs scale 1-10 (talc is the softest - 1; diamond is hardest – 10)

Luster How well does it reflect light? Metallic shiny, non-metallic is dull.

Color Distinct; yellow for sulfur and purple for amethyst

Streak Color left on tile

Cleavage Smooth break like mica

Fracture Rough break like quartz

Other Tests Smell, Magnet, Acid Test, Double Refraction

Uses of Minerals• Gems-rare, beautiful, highly prized minerals• Ores-mineral mined for a profit• Titanium-Strong, lightweight, nontoxic ore

that can be used in airplanes, artificial body parts, sporting equipment, wheelchairs, etc.

Other Uses of Minerals