Böhmite

Also known as boehmite

minerale

Mineral.name: Boehmite
Mineral.category: Oxide mineral
Mineral.image: Böhmite-89904.jpg
Mineral.imagesize: 260px
Mineral.caption: Böhmite and Natrolite from Sagåsen (Strandåsen), Mørje, Porsgrunn, Telemark, Norway (Field of view 10 mm)
Mineral.formula: γ-AlO(OH)
Mineral.IMAsymbol: Bhm
Mineral.strunz: 4.FE.15
Mineral.dana: 6.1.2.1
Mineral.system: Orthorhombic
Mineral.class: Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Mineral.symmetry: Amam
Mineral.unit cell: a = 3.693 Å, b = 12.221 Å, c = 2.865 Å; Z = 4
Mineral.color: White, pale greyish brown; yellowish or reddish when impure; colorless in thin section
Mineral.habit: Tabular crystal rare, fine grained in pisolitic aggregates or disseminated
Mineral.cleavage: Very good on {010}, good on {100}, and poor on {001}
Mineral.fracture: Uneven
Mineral.refractive: nα = 1.644 – 1.648 nβ = 1.654 – 1.657 nγ = 1.661 – 1.668