The Wild, Wacky World of Minerals

Intro to Minerals

I. A mineral is… A) Inorganic: 1. Not made up of living things. 2. Not made from the remains of living things. B) Naturally formed solid: 1. Minerals are formed by nature. 2. They always exist in solid form at surface temperatures. 3. They have a fixed internal structure.

C)Specific chemical formula 1. All minerals have a specific chemical composition. 2. A mineral can be one or more types of atoms. a.) Gold has one type of atom. b.) Fluorite is a compound of more than one type of atom.

II. Mineral Groups A) Silicate Minerals: contain a combination of silicon and oxygen. 1. 96% of the Earth’s crust is silicon and oxygen 2. Feldspor is the most common mineral, making up to one half the crust.

B) Non Silicate Minerals: does not have combination of silicon and oxygen. 1. Only 4% of the Earth’s crust is Non Silicate. 2. Metals like copper, silver, and gold. 3. Non metals like sulfur.

III. Mineral Identification A. Color 1. Because many minerals are the same color, color is not a strong identifier. 2. Some minerals are formed in different colors.

B. Hardness: A minerals resistance to being scratched. 1. Mohs Hardness Scale A) 1. Talc 2 Gypsun 3. Calcite 4. Flurorite 5. Apatite 6. Corundum 7. Quartz 8. Topaz 9. Corundum 10. Diamond 2. Field Hardness Test A)2.5 Fingernail 3.5 Penny 4.5 Nail 5.5 Glass 7Quartz

C. Cleavage-Fracture 1. Cleavage is a minerals tendency to split along sets of parallel flat surfaces. 2. Fracture is a minerals tendency to split along irregular shapes

D. Streak 1. Streak is the color of the powder left by a mineral when it is rubbed against a hard rough surface. 2. A mineral streak may be different than it’s color. E. Luster: How a mineral reflects light.

IV. Special Properties A. Taste, is a bad way to find a mineral B. Fluorescence: ability to glow and to change color under ultraviolet light C. Double Refraction: a mineral that produces a double image D. Radioactivity: minerals can give off nuclear radiation when the atom changes.

V. Uses and Importance of Minerals A. Minerals are cool because: 1. conduct heat and electricity 2. made into electrical wires 3. hammered into sheets 4. cannot break easily B. Ductility: is the ability to be drown or pulled into wire.

C. Brittle- If a mineral is hammered and the result is powder or small crumbs it is considered brittle. 1. The majority of all minerals are brittle

D. Malleable-If a mineral can be flattened by pounding with a hammer, it is malleable/ 1. All true metals are malleable. (silver, gold) E. Ductile-A mineral that can be stretched into a wire is ductile. 1. All true metals are ductile.