Forsterite
Mg2SiO4
Chemical name
Forsterite
Mineral name
Forsterite
Chemical formula
Mg2SiO4
Melting point [°C]
1895
Crystal system
orthoromic
Crystal Class
orthorhombic-dipyramidal (2/m 2/m 2/m)
Space Group
Pbnm
Unit cell
a [Å]:4.77
b [Å]:10.28
c [Å]:6.00
Formula units
Z=4
Mohs hardness
7
Density [g/cm3]
3.217
Cleavage
good on {001}, clear on {010}
Fracture / Tenacity
conchoidal to uneven
Color
colorless, grey, white, green, yellowish green to blackish green
Streak
white
Transparency
transparent to translucent
Optical character
biaxial (+)
Refractive Index
nα=1..635; nβ=1.651; nΥ=1.670
Birefringence δ
0.033 - 0.042