Mineral phase
- IMA name
- Forsterite
- Class
- silicate mineral
- Compound type
- nesosilicate
- Comments
- Forsterite: name by extension of (Fe,Mg)2SiO4 in the range Fe=0-10% - Equivalent Space Group: Pbnm (62)
- Formula
- $Mg_2.SiO_4$
- Chemical formula
- Mg2SiO4
- Elemental formula
- Mg2 Si O4
- Isotope mixture type
- terrestrial abundance
- Oxides
-
Formula $MgO$ $SiO_{2}$ Mass fraction (%) 57.29 42.71
Strunz
- Class
- silicates (09)
- Division
- nesosilicate (09.A)
- Family
- Nesosilicates without additional anions; cations in octahedral [6] coordination (09.AC)
- Code
- 09.AC.05
Dana
- Major class
- silicates (VIII)
- Class
- nesosilicate insular SiO4 groups only (51)
- Type
- with all cations in octahedral [6] coordination (51.03)
- Group
- Olivine group (51.03.01)
- Code
- 51.03.01.02
- Phase type
- crystalline
- Crystal system
- orthorhombic
- Crystal class
- dipyramidal
- Crystal class symbol
- mmm (D2h)
- Crystal spacegroup
- Pnma
- Composition order
- ordered
- Molar mass
- 140.69 $g/mol$
- Density
- 3.271 $g/cm^3$
- State NTP
- solid
- Refringence type
- biaxial
- Refringence sign
- negative
- Birefringence
- 0.0330
- Refraction index $n_{\alpha}$
- 1.636
- Refraction index $n_{\beta}$
- 1.650
- Refraction index $n_{\gamma}$
- 1.669
- Dispersion V
- r > v or r < v
- Pure color
- green
- Color
- green, yellow, yellow green, white
- Diaphaneity
- transparent to translucent
- Luster
- vitreous