Mineral - Cyanotrichite
Cyanotrichite
Chemical Properties
Mineral Class
Sulphates
Toxicity
none
Formula
Cu₄Al₂(SO₄)(OH)₁₂ · 2 H₂O
Unit Cell
a=10.16 b=12.61 c=2.90 Z=1
Physical Properties
Hardness
2
Streak
blue
Density
Normal (2-3,5)
Cleavage
Fracture
Tenacity
Optical Properties
Color
blue
Birefringence
0.067
Luster
Silky
Transparency
translucent,
transparent
Pleochroism
X = Farblos
Y = Farblos-Blau
Z = Blau
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
C2/m (12)
Habit
fibrous, acicular, radial
Formation
Oxidationszone von Kupfer-Lagerstätten
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Cyanotrichite
Composition
Elements
Mass
SO₃
12.19
Al₂O₃
15.59
Fe₂O₃
0.43
CuO
47.50
CaO
0.11
H₂O
23.20
USA (Palache et al. 1952)
Groups and Members
Cyanotrichite-Group