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 Plasma Naturally Occurring: Not Human- Made Inorganic: Not Alive - Never Was Fixed 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 properties 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 Resources 1.Many uses in industry: machines, technology and everyday products 2.Use in the arts: paint, dyes, gemstones, jewelry

3. Minerals crystals form in several ways Water evaporates Hot Water cools Molten rock cools-the quicker it cools, the smaller the crystals formed. Magma-molten rock inside the Earth Lava-molten rock on the Earth’s surface Heat and pressure cause mineral changes deep in the Earth

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