Mineral - Diaspore
Diaspore
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
none
Formula
AlO(OH)
Unit Cell
a=4.40 b=9.43 c=2.85 Z=4
Physical Properties
Hardness
6.5 - 7
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {010}, distinct after {110}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
brownyellowpinkcolorless
Birefringence
0.048
Luster
Vitreous,
Pearly
Transparency
translucent,
transparent
Pleochroism
X = Violett-Blau
Y = Violett-Rot
Z = Grün
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pnma (62)
Habit
massive
Formation
hydrothermal, Metamorphose
Paragenesis
Twinning
V-shaped contact twins after {021}
Rarity
Rarely
Synonyms
Diaspore
Composition
Elements
Mass
SiO₂
0.42
Al₂O₃
84.44
Fe₂O₃
0.18
H₂O
14.99
Russia (Palache et al. 1952)
Groups and Members
Diaspore-Group