Identification of Minerals

Luster Cleavage Color Name Properties

Metallic Luster Cleavage present Galena

Shiny, silver-­‐gray; excellent cubic cleavage

No Cleavage Graphite Shiny, silver-­‐gray; no form

Pyrite Brassy-­‐yellow; often as a collection of cubic crystals

Plagioclase Light gray-­‐white color; two planes of cleavage at 90°

Microcline (Orthoclase)

Peachy-­‐pink color; two planes of cleavage at 90°

Light in Color Muscovite

Clear-­‐light brown; one plane of cleavage; transparent-­‐translucent

Cleavage Present Calcite

Clear-­‐white; transparent-­‐ translucent; cleavage at 75°

Gypsum Clear-­‐white; transparent-­‐ translucent; one good plane of cleavage, two poor planes

Non-­‐metallic Luster Halite

Clear-­‐white; transparent-­‐ translucent; cubic cleavage

Augite Dark green; cleavage planes at 90°

Dark in Color Hornblende

Black; cleavage planes at 60° and 120°

Biotite Clear-­‐black; one plane of cleavage; transparent-­‐translucent

Light in Color Quartz Clear-­‐translucent; no cleavage

Cleavage Absent Kaolinite Chalk-­‐like; white

Dark in Color Hematite Red-­‐brown; small round nodules