Minerals Are:* Solid, inorganic materials that form naturally on or beneath the E’s surface.

•Have a definite chemical composition.

•Usually solid. High temp. inside the Earth can melt them.

• Inorganic – not made from things that were once alive.

•Naturally Occurring – not man-made. Formed as a result of processes in the natural world.

•Have definite crystal structure – repeating patterns of a mineral’s atoms.

•Use a magnifying glass to see “flat edges” where breaks have occurred.

•Definite Chemical Composition –

Each type of mineral has the same proportions of the same elements.

How Mineral Form

• Most minerals form when molten material (magma) cools and hardens inside Earth or on the surface

• Some form when a solution evaporates on Earth’s surface– Ex. Halite NaCl

How Minerals are Formed

• If magma or lava cool slowly then large crystals will form– Ex. Quartz

• If magma or lava cool quickly the small crystals will form– Ex. Feldspar

Identify Minerals•Look at the Properties – characteristics that make that mineral different from other minerals.

Ways to Identify:•Hardness•Color•Streak•Luster•Cleavage•Density

Identifying Minerals

• Hardness- use Moh’s hardness scale p 95 of textbook

Color

• Not good to use.

• Several minerals come in different colors.

Streak

• - color of the mineral’s powder found when the mineral is rubbed on a piece of tile

Luster• - how a mineral reflects light: glassy,

pearly, metallic, and earthy

Cleavage & Fracture

•Cleavage: split apart easily along flat surfaces.

•Fracture: irregular surface where it breaks

Cleavage

Fracture

Density

• Density = mass/volume

• Use a balance to find mass in grams

• Use a graduated cylinder to find volume in milliliters

Other Properties:• Chemical reaction: fizzes with vinegar (Calcite)

• Transparent – can see through it

• Opaque – pearly, cloudy

• Magnetic * High Mass