1. Composition and Structure of Minerals

2.  It occurs naturally  It is a solid  It has a definite chemical composition  Its atoms are arranged in an orderly pattern (specific crystal shape)  It is inorganic (it was never alive)

3.  ~4000 known minerals  Examples: quartz, gold, halite and diamond  Most minerals are compounds  Quartz: compound of Silicon and oxygen

4.  Regular geometric shape with smooth surfaces (the crystal faces)  All minerals have crystalline structures.  Only 6 basic types of crystal shapes

5.  Reflectance of light off surface of a mineral  Either metallic luster or non-metallic categories  NM subcategories: pearly, earthy, greasy, or glassy appearances. Metallic Minerals Non-metallic Minerals

6.  Crystal structure determines how mineral cleaves (breaks); splits along weak bonds; based on number of PARALLEL planes  Fracture: irregular pattern of breakage in directions other than along cleavage planes

7.  Resistance of a mineral to scratching.  In class, we will do a greater than or less than comparison.  If the mineral is not scratched by a penny and does not scratch glass, then 3< mineral < 5.5.  Talc can be scratched with a fingernail, so we would say the hardness is <2.5

8.  Property of mineral that describes its color in powdered form.  TEST: Use a streak plate (tile) to determine the mineral’s streak.

9.  Easy to see  Does NOT distinguish one mineral from another  NOT a defining test to determine a mineral.

10.  Some minerals react when placed within a magnetic field.  Some strongly attracted to the magnet, some weakly attracted, and one mineral is actually repelled.

11. All carbonate minerals fizz when weak hydrochloric acid is applied to them.

12.  Comparison of weight of mineral in air with weight suspended in water  Density = mass/volume

13.  Luster  Cleavage  Streak  Hardness  Color  Specific Gravity  Magnetism  Acid Test  Video Video  Video cleavage and hardness start at min 1:22cleavage and hardness