Mineral - Braunite
Braunite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Mn²⁺Mn³⁺₆[O₈|SiO₄][
Unit Cell
Physical Properties
Hardness
6 - 6.5
Streak
black
Density
Heavy (3,5-6)
Cleavage
Fracture
Tenacity
Optical Properties
Color
black
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
tetragonal
Point Group
ditetragonal-dipyramidal - 4/m 2/m 2/m
Space Group
I4 1 /acd (142)
Habit
coarse, crusty, pyramidal, tabular
Formation
Oxidation zone of manganese deposits, metamorphism
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Braunite
Groups and Members
Braunite-Group