Mineral - Enstatite
Enstatite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Mg₂Si₂O₆
Unit Cell
a=18.23 b=8.84 c=5.19 Z=8
Physical Properties
Hardness
5 - 6
Streak
white
Density
Normal (2-3,5)
Cleavage
Distinct after {210}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
whitebrownyellowgreencolorless
Birefringence
0.011
Luster
Vitreous,
Pearly
Transparency
translucent,
transparent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pbca (61)
Habit
blocky, fibrous, acicular, prismatic, tabular
Formation
Magmatic, Metamorphism
Paragenesis
Twinning
Rarity
Common
Synonyms
Enstatite
Composition
Elements
Mass
SiO₂
58.84
Al₂O₃
0.88
Fe₂O₃
0.72
Cr₂O₃
0.25
FeO
3.93
MnO
0.02
MgO
34.71
CaO
0.50
Na₂O
0.23
K₂O
0.08
H₂O
0.21
Lesotho (Dana 1895)
Groups and Members
Pyroxene-Group
Orthopyroxene-Subgroup