Mineral - Torbernite
Torbernite
Chemical Properties
Mineral Class
Phosphates
Toxicity
radioactive
Formula
Cu(UO₂)₂(PO₄)₂ · 12H₂O
Unit Cell
a=7.03 c=20.81 Z=2
Physical Properties
Hardness
2 - 2.5
Streak
green
Density
Normal (2-3,5)
Cleavage
Perfect after {001}
Fracture
Tenacity
Brittle
Optical Properties
Color
green
Birefringence
0.010
Luster
Vitreous,
Pearly
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
tetragonal
Point Group
ditetragonal-dipyramidal - 4/m 2/m 2/m
Space Group
I4/mmm (139)
Habit
leafy, dipyramidal, pyramidal, tabular
Formation
Secondary, through the aqueous oxidation of primary uranium minerals (particularly uraninite) in the oxidation zone of hydrothermal ore deposits in the presence of copper ions and phosphoric acid
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Torbernite
Composition
Elements
Mass
UO₃
57.03
P₂O₅
14.50
SiO₂
0.59
CuO
7.73
H₂O
20.30
Germany (Palache et al. 1952)
Groups and Members
Autunite-Group