1. DEFINITION OF MINERAL Naturally occurring, Inorganic Solid with a definable chemical composition and crystal structure Physical Properties Crystal Form (Shape)

2. Cubic - Fluorite

3. Dodecahedron - Garnet

4. Hexagonal Prism - Quartz

5. Octahedron - Magnetite

6. Cleavage Page 22 Tendency to break along planes of weaker atomic bonds. Cleavage produces flat, shiny surfaces. Described by the number of planes and their angles.

7. Potassium Feldspar Muscovite mica Amphibole Examples of cleavage –One direction –Two directions at 90º –Two directions NOT at 90º

8. Calcite Examples of cleavage Three directions at 90º Three directions NOT at 90º

9. Fracture Example: quartz displays conchoidal fracture. Shaped like the inside of a clam shell. Breaks along smooth curved surfaces.

10. Specific Gravity The weight of a mineral compared to the same volume of water Luster Page 23 Intensity of light reflected off a mineral Metallic, non-metallic- glassy (vitreous) and earthy (dull) Color and Streak

11. Scratching resistance of a mineral. Derives from the strength of atomic bonds. Hardness compared to the Mohs scale for hardness. 1.Talc, graphite 2.Gypsum 3.Calcite 4.Fluorite 5.Apatite 6.Orthoclase 7.Quartz 8.Topaz 9.Corundum 10.Diamond Hard- Scratches Glass Soft - Scratched by Fingernail Medium - Does not scratch glass, not scratched by Fingernail Hardness

12. Other Properties Reaction with acid Taste Magnetism