Mineral Species: Bixbyite

Chemical Formula: (Mn+++,Fe+++)2O3

Chemical Name: Manganese Iron Oxide

Mineral Class: Oxide

Mineral Notes: Bixbyite is named after the American mineralogist, M. Bixby. The mineral occurs in pneumatolytic, hydrothermal, and metamorphic rocks. The crystals of Bixbyite are usually cubes with modified corners. These can lead the crystals to have a pseudo octahedral or psedo dodecahedral habit. If all three forms are present the crystal can look extremely complex and unusual. The mineral can be an important source of managnese.

Description: A white matrix in which sit two black crystals of Bixbyite. Both show the expected distorted cubic form. The larger of the two appears to be twinned. The specimen is notable for its strong metallic luster.

Location: Topaz Mountain, Thomas Range, Utah, USA.