Constituent
- Name
- Forsterite
- 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)
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Formula
- $Mg_2.SiO_4$
- Chemical formula
- Mg2SiO4
- Elemental formula
- Mg1.788 Si1.002 O4 Ca0.002 Al0.001 Mn0.003 Fe0.201
- Isotope mixture type
- terrestrial abundance
- Composition comments
- Common substitution: Fe
- Oxides
-
Formula $FeO$ $SiO_{2}$ $MgO$ $CaO$ $MnO$ $Al_{2}O_{3}$ $Cr_{2}O_{3}$ $ZnO$ $BaO$ Mass fraction (%) 9.77 40.79 48.8 0.07 0.14 0.02 0.02 0.02 0.01
Strunz
- Class
- silicates (09)
- Division
- nesosilicate (09.A)
- Family
- 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
- 147.12 $g/mol$
- Density
- 3.271 $g/cm^3$
- 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
- Color
- green, yellow, yellow green, white
- Diaphaneity
- transparent to translucent
- Luster
- vitreous