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