1. BACKGROUND:  Scientists have identified over 2000 different minerals in the earth's crust.95% of the earth's crust is composed of only 12 different rock-forming minerals.

A. Minerals are all around us

2. What is a mineral?

All natural earth materials are made of minerals or a combination of minerals Minerals are the building blocks of rocks

3. Characteristics

Solid: Not Liquid or Gas or PlasmaNaturally Occurring: Not Human-Made

Inorganic: Not Alive - Never WasFixed Composition: Same Recipe, Everywhere, Every Time (single element or compounds-no mixtures)Crystal Form: specific repeating atom arrangement

( remember SNIFC)

The most common group are the silicates which contain silicon and oxygen which are also the most common elements in the Earth's crust.

4.Minerals are grouped according to their composition

B. A mineral is Identified by its B. A mineral is Identified by its propertiesproperties

1. A mineral’s appearance helps identify it• Color-not very reliable• Luster-How does light reflect off of it?

• Metallic or non-metallic• Streak-the color of a thin powder line left by

the mineral-EVERY time• Breakage-evenly (cleavage) or randomly

(fracture)?• Density-mass per unit of volume ; D=m/v• Hardness-resistance to scratching; Moh’s

Scale helps to identify• Special properties include radioactivity,

magnetism, reaction to acid or UV reaction

C. Minerals are Valuable Resources1.Many uses in industry:

machines, technology and everyday products

2.Use in the arts: paint, dyes, gemstones, jewelry

3. Minerals crystals form in 3. Minerals crystals form in several waysseveral ways

Water evaporatesWater evaporates

Hot Water coolsHot Water cools

Molten rock cools-the quicker it Molten rock cools-the quicker it cools, the smaller the crystals cools, the smaller the crystals formed.formed.

MagmaMagma-molten rock inside the -molten rock inside the EarthEarth

LavaLava-molten rock on the Earth’s -molten rock on the Earth’s surfacesurface

Heat and pressure cause mineral Heat and pressure cause mineral changes deep in the Earthchanges deep in the Earth

4. Minerals can be mined for a 4. Minerals can be mined for a profit. When they are, they are profit. When they are, they are called called oresores