Böhmite (Boehmite)

Formula:  AlO(OH)

Origin of name:  For J. Böhm, German geologist

Crystal system:  Orthorhombic

Crystal class:  Unknown

Twinning:

Unit cell: a = 3.70 Ǻ, b = 12.23 Ǻ, c = 2.87 Ǻ

Colour:  White, brown

Diaphaneity:

Luster:

Habit:

Hardness:  3

Specific gravity:  3.070

Cleavage:  2; {010} perfect, {100} good

Tenacity:

Streak:

Synonyms/varieties:

Comments: Dimorphous with diaspore