Bixbyite
Image: Didier Descouens (CC BY-SA 3.0)
Mineral NameBixbyite
Chemical Formula(Mn,Fe)2O3
Mohs Hardness6
Crystal Systemcubic
Lustermetallic
Streak Colorblack
Cleavagenone
Fractureconchoidal
Specific Gravity4.9
Colorsblack
Transparencyopaque
Type LocalityMaynard's Claim (Pismire Knolls), Thomas Range, Juab Co., Utah, USA
Mineral GroupOxides
Usescollector
Associated Mineralstopaz, red beryl, pseudobrookite, hematite, garnet
Rarityuncommon
Description
A sharp, lustrous black bixbyite crystal, approximately 1 cm in size, exhibiting cubic habit and embedded in a light-colored, granular matrix.
Geological Context
Bixbyite typically forms in gas cavities (vugs) within rhyolitic volcanic rocks, often associated with other rare minerals formed under high-temperature, low-pressure conditions.
