Forsterite

Color: various shades of green, from yellow-green to olive green to greenish black, also white, brown or black

Streak: Colorless

Luster: vitreous to greasy

Habit: crystals thick tabular, massive, compact or granular

Hardness: 7

Specific gravity: 3.28 to 4.32

Cleavage: 2; {010} and {100} imperfect

Tenacity: Brittle

Twinning: Common on {100}, contact, simple, repeated; on {001}, lamellar

Crystal system: orthorhombic

Crystal class: 2/m 2/m 2/m