Mineral - Hübnerite
Hübnerite
Chemical Properties
Mineral Class
Tungstate
Toxicity
none
Formula
Mn²⁺WO₄
Unit Cell
a=4.83 b=5.75 c=4.99 β=91° Z=2
Physical Properties
Hardness
4 - 4.5
Streak
brownredred brown
Density
Very Heavy (>6)
Cleavage
Perfect after {010}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
blackbrownred
Birefringence
0.130
Luster
Metallic
Transparency
translucent,
transparent
Pleochroism
X = Rot
Y = Rot-Gelb
Z = Rot-Grün
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2/c (13)
Habit
prismatic, tabular
Formation
In veins of hydrothermal ore deposits
Paragenesis
Twinning
Contact twins after {100}
Rarity
Rather rare
Synonyms
Hübnerite, Hubnerite
Composition
Elements
Mass
SiO₂
0.62
WO₃
75.58
(Nb,Ta)O₅
0.05
FeO
0.24
MnO
23.40
CaO
0.13
Colorado (Palache et al. 1951)
Groups and Members
Columbite-Supergroup
Wolframite-Group