Diaspore
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameDiaspore
Chemical FormulaAlO(OH)
Mohs Hardness6.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {010}, good on {110}, distinct on {100}
Fractureconchoidal
Specific Gravity3.35
Colorsbrown, pink, yellow, white, gray, violet, green
Transparencytransparent
Type LocalityMugla Province, Aegean Region, Turkey
Mineral Grouphydroxides
Usesgemstone, collector, minor aluminum ore
Associated Mineralsmargarite, corundum, chloritoid, gibbsite, boehmite
Rarityuncommon
Description
This specimen features brownish-pinkish, tabular to bladed crystals of diaspore, often exhibiting a vitreous luster and good crystal faces. Some crystals show a slight translucency.
Geological Context
Diaspore typically forms in bauxite deposits, emery deposits (metamorphosed bauxite), and hydrothermal alteration zones of aluminum-rich rocks. It is a product of the alteration of aluminum silicates.
