Constituent
Name
Ortho-enstatite
IMA name
Orthopyroxenes subgroup
Class
silicate mineral
Compound type
inosilicate
Constituent abundance in material
Relevance
main - major
Arrangement
single phase
Mass
1.0 $g$
Mass fraction
1.0
Chemical composition
Formula
Mg$_{0.92}$Fe$_{0.09}$SiO$_{3}$
Chemical formula
Mg0.92Fe0.09SiO3
Elemental formula
(Mg)0-1 (Fe2+)0-1 (Si)1-2 (O)3-6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mg$ Magnesium element 0 - 1 1.0 constituent element main
$Fe^{2+}$ Iron(II) cation element 0 - 1 1.0 constituent element main
$Si$ Silicon element 1 - 2 1.0 constituent element main
$O$ Oxygen element 3 - 6 1.0 constituent element main
Composition comments
Common impurities: Al, $Fe^{3+}$, Ca, Na, K, Co, Ni, Mn, Ti, Cr
Oxides
Formula $FeO$ $MnO$ $MgO$ $SiO_{2}$
Mass fraction (%)

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)
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
dipyramidal
Crystal class symbol
mmm (D2h)
Crystal spacegroup
Pbca
Molar mass
200.78 - 263.86 $g/mol$
Density
3.10 - 4.02 $g/cm^3$
Refringence type
biaxial
Refringence sign
positive or negative
Birefringence
0.009 - 0.021
Refraction index $n_{\alpha}$
1.650 - 1.767
Refraction index $n_{\beta}$
1.652 - 1.770
Refraction index $n_{\gamma}$
1.659 - 1.788
Dispersion V
weak to strong (r < v)
Color
green
Diaphaneity
transparent to opaque
Luster
vitreous