Bixbyite

Formula: Mn3+2O3 or (Mn, Fe)2O3

Colour: Black

Lustre: Metallic

Hardness:  6 – 6½

Specific Gravity: 4.945

Crystal System: Isometric mostly cubic

Name: For Maynard Bixby (1853-1935), prospector, miner, mine broker, author, explorer of the Thomas Range, and mineral dealer of Salt Lake City, Utah, USA, who collected and provided the first specimens discovered in 1897.

Type Locality: Maynard’s Mine, Pismire Knolls, Thomas Range, Juab County, Utah – USA.

The Mn analogue of Bixbyite-(Fe); newly defined in December 2021 (IMA 21-H).

Belongs to the Bixbyite Series.
Bixbyite is a manganese iron oxide mineral. The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a somewhat rare mineral sought after by collectors as it typically forms euhedral isometric crystals exhibiting various cubes, octahedra, and dodecahedra.