Boehmite
Mineral AlO(OH)
Also called Böhmite
About it
Mostly a fine-grained, earthy part of bauxite, mixed with gibbsite and diaspore; distinct crystals are rare. Named for the chemist Johann Böhm, who studied aluminium hydroxides.
- Type
- Mineral
- Group
- Hydroxide, boehmite group
- Formula
- AlO(OH)
- Hardness (Mohs)
- 3–3.5
- Specific gravity
- 3–3.07
- Streak
- white
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Orthorhombic
- Colours
- white, pale yellow, pale green, brown
- Transparency
- transparent, translucent
- Cleavage and fracture
- very good in one direction
Typical values: real specimens vary. For more, see mindat.org.