Constituent
Name
Orthopyroxene Fs23 Wo1
IMA name
Enstatite-Ferrosilite series
Class
silicate mineral
Compound type
inosilicate
Relevance
main - major
Arrangement
homogeneous in multi-phases
Mass fraction
0.269 ± 0.004
Formula
(Ca0.01,Fe0.232+,Mg0.76)2.[SiO3]2
Chemical formula
(Ca)0.02(Fe2+)0.46(Mg)1.52Si2O6
Elemental formula
Ca0.02 (Fe2+)0.46 Mg1.52 Si2 O6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Ca Calcium element 0.02 1.0 constituent element main
Fe2+ Iron(II) cation element 0.46 1.0 constituent element main
Mg Magnesium element 1.52 1.0 constituent element main
Si Silicon element 2 1.0 constituent element main
O Oxygen element 6 1.0 constituent element main
Composition comments
perfect solid solution - Common impurities: Al, Fe3+, Na, K, Co, Ni, Mn, Ti, Cr - Hypersthene is old name for mid-way member between Enstatite and Ferrosilite - C
Oxides
Formula CaO FeO MgO SiO2
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
amorphous
Crystal system
amorphous
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/cm3
Refringence type
biaxial
Refringence sign
positive
Birefringence
0.009 - 0.021
Refraction index nα
1.650 - 1.767
Refraction index nβ
1.652 - 1.770
Refraction index nγ
1.659 - 1.788
Dispersion V
weak to strong (r < v)
Color
colorless, white, greenish white, yellowish green, green, gray, brown, dark brown, black
Diaphaneity
translucent to opaque
Luster
vitreous