Bahianite Locality: Serra da Mangabeira, Paramirim, Bahia, Brazil Size: 2.0 cm x 1.0 cm x 1.0 cm A dull to glossy, muddy mocha colored, 20x10mm, stream-worn pebble of this exotic aluminum-antimony oxide-hydroxide accompanied by original Richard Gaines and typewritten Rock Currier labels. Ex. Rock Currier collection. Tom and Melissa Campbell photos. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Bahianite
Bahianite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Al₅Sb⁵⁺₃O₁₄(OH)₂.
It crystallizes in the monoclinic crystal system (space group C2/m).
Key properties: Mohs hardness 9; specific gravity 4.78–5.29; Adamantine luster; optically biaxial.
IMA symbol Bhi, IMA status: approved, named in 1974.
Found in potholes as stream-worn pebbles and as residual concentrates above weathered volcanic rock.
It is found associated with Quartz, andalusite, kyanite, diaspore, phenakite, eskolaite, cassiterite, gold.
The name refers to the occurrence in Bahia, Brazil.