Mineral phase
IMA name
Ferrosilite
Class
silicate mineral
Compound type
inosilicate
Comments
Ferrosilite: name by extension of $(Fe,Mg)_2Si_2O_6$ in the range Mg=0-10%
Formula
$Fe^{2+}_2.[SiO_3]_2$
Chemical formula
(Fe2+)2Si2O6
Elemental formula
(Fe2+)2 Si2 O6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Fe^{2+}$ Iron(II) cation element 2 constituent element main
$Si$ Silicon element 2 constituent element main
$O$ Oxygen element 6 constituent element main
Composition comments
Common substitution: Mg, $Mn^{2+}$ - Common impurities: Al, $Fe^{3+}$, Ca, Na, K, Co, Ni, Mn, Ti, Cr
Oxides
Formula $FeO$ $SiO_{2}$
Mass fraction (%) 54.45 45.55

Strunz

Class
silicates (09)
Division
inosilicate (09.D)
Family
with 2-periodic single chains, Si2O6; pyroxene family (09.DA)
Code
09.DA.05

Dana

Major class
silicates (VIII)
Class
inosilicate single-width unbranched chains, w=1 (65)
Type
with chains P=2 (65.01)
Group
Orthopyroxenes (65.01.02)
Code
65.01.02.02
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
dipyramidal
Crystal class symbol
mmm (D2h)
Crystal spacegroup
Pbca
Molar mass
263.86 $g/mol$
Density
3.6 - 4.0 $g/cm^3$
State NTP
solid
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.016 - 0.021
Refraction index $n_{\alpha}$
1.710 - 1.767
Refraction index $n_{\beta}$
1.723 - 1.770
Refraction index $n_{\gamma}$
1.726 - 1.788
Dispersion V
strong (r < v)
Pure color
colorless
Color
colorless, green
Diaphaneity
translucent
Luster
vitreous