Bixbyite
Image: Andrew Silver (Public domain)
Mineral NameBixbyite
Chemical Formula(Mn,Fe)2O3
Mohs Hardness6
Crystal Systemcubic
Lustermetallic
Streak Colorblack
Cleavagenone
Fractureconchoidal
Specific Gravity4.9
Colorsblack
Transparencyopaque
Type LocalityThomas Range, Juab County, Utah, USA
Mineral GroupOxides
Usescollector
Associated Mineralstopaz, beryl, garnet, hematite, pseudobrookite
Rarityuncommon
Description
This specimen displays sharp, black, cubic crystals of bixbyite, exhibiting a distinct metallic luster. The crystals are well-formed and appear to be embedded in a matrix or as individual euhedral crystals.
Geological Context
Bixbyite typically forms in rhyolitic volcanic rocks, often in vugs or cavities, as a result of high-temperature hydrothermal activity. It can also be found in manganese-rich metamorphic deposits.
