Mineral - Bixbyite-(Mn)
Bixbyite-(Mn)
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
none
Formula
Mn³⁺₂O₃
Unit Cell
a=9.41 Z=16
Physical Properties
Hardness
6 - 6.5
Streak
black
Density
Heavy (3,5-6)
Cleavage
Imperfect after {111}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
black
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
isometric
Point Group
diploidal - 2/m 3
Space Group
Ia 3 (206)
Habit
Deltoidal icositetrahedron, dodecahedron, Hexakis octahedron, Triacis octahedron, Cube
Formation
hydrothermal, Metamorphose
Paragenesis
Twinning
Penetration twins after {111}
Rarity
Rather rare
Synonyms
Bixbyite-(Mn), Bixbyite, Manganbixbyite, Partridgeite, Sitaparite
Composition
Elements
Mass
Al₂O₃
2.02
Fe₂O₃
14.86
Mn₂O₃
82.56
MgO
0.07
South Africa (Montgomery 1934)