Minerals

Gypsum

Vitreous to silky, perfect cleavage, one direction, plus 2 indistinct

Corundum

Vitreous, hexagonal or pyramidal crystals, fracture

Calcite

Vitreous, reacts with HCl, perfect cleavage, 3 directions, rhombic

Apatite

Vitreous, poor cleavage in one direction, otherwise fracture

Quartz

Vitreous to greasy, hexagonal crystals, fracture (conchoidal)

Pyrite

Metallic, cubic, fracture (conchoidal)

Plagioclase

Vitreous, pearly on cleavage plains, two direction @ 90, striations

Hematite (Metallic and Nonmetallic)

Metallic or submetallic, sometimes rounded, fracture

Earthy, fracture

Galena

Metallic, cubic cleavage

Limonite

Dull earthy, fracture

Hornblende

Vitreous, two direction cleavage @ 56 and 124 degrees

Biotite

Vitreous, flaky, perfect cleavage, one direction

K-Spar

Vitreous, pearly on cleavage, smooth cleavage, two directions @ 90 degrees

Halite

Vitreous, cubic cleavage, 3 directions @ 90 degrees

Muscovite

Vitreous to pearly, clear sheets, perfect cleavage, one direction

Magnetite

Metallic or submetallic, fracture

Olivine

Vitreous, fracture (conchoidal)

Garnet

Vitreous to resinous, fracture

Fluorite

Vitreous, perfect cleavage, 4 directions