Magnesium Silicate
MgSiO3
Chemical name
Magnesium Silicate
Mineral name
Enstatite
Chemical formula
MgSiO3
Crystal system
orthorhombic
Crystal Class
orthorhombic-dipyramidal (2/m 2/m 2/m)
Space Group
Pbca
Unit cell
a [Å]:18.23
b [Å]:8.84
c [Å]:5.19
Formula units
Z=8
Frequent crystal surfaces
{010}, {210}, {311}, {111}
Twinning
simple or lamellar on {100}
Mohs hardness
5 - 6
Density [g/cm3]
~3.2
Cleavage
good on {210}
Fracture / Tenacity
brittle, uneven
Color
colorless, white, gray, yellowish-green, olive, brown
Streak
white
Transparency
translucent to opaque
Optical character
biaxial (+)
Refractive Index
nα=1.650-1.668; nβ=1.652-1.673; nΥ=1.659-1.679
Birefringence δ
0.010
Pleochroism δ
moderate