 Definition: Color of the mineral  Downfall: mineral can occur in different colors  Example quartz can be found in three different colors

 Definition: the appearance of a mineral in reflected light.  Example: Metallic (looks like metal), and non-metallic (glassy, dull, greasy, silky or brilliant)  Downfall: Personal perception of the definition of each luster category make it hard to categorize in a definite and uniform manner Metallic luster

Greasy Glassy Dull silkybrilliant

 Definition: the ability of a mineral to resist being scratched. Degree of hardness is described on Moh’s scale of 1-10  Problem: Personal perception of when a mineral becomes scratched makes it difficult to assign a uniform value.

FINGERNAIL IS A 2.5 GLASS IS A TALC TALCUM POWDER, BABY POWDER GYPSUM BUILDING MATERIALS (SHEETROCK) CALCITE CEMENTS FLUORITE TOOTHPASTE APATITE FERTILIZER FELDSPAR FLOOR TILES QUARTZ WATCHES, ABRASIVES TOPAZ GEMSTONES (EMERALD) CORUNDUM GEMSTONES (RUBY & SAPHIRE) DIAMOND SAW BLADES, “ AGIRL ’ S BEST FRIEND ” MINERAL NAME TYPICAL USES

 Definition: physical property that describes the way a mineral breaks.  Breaking occurs along planes of weakness in the mineral.  Down fall: hard to tell the planes apart Albite: 2 planes of cleavage

 Definition: The shape that mineral assumes when it crystallizes.  Downfall: if specific conditions aren’t met the mineral will not form the Crystal shape.

 Definition: The color of a mineral when it is in a powdered form.  Downfall: Can’t do the streak test on objects that are harder than the streak plate.