Constituent
- Name
- Orthopyroxenes
- IMA name
- Orthopyroxenes subgroup
- Class
- silicate mineral
- Compound type
- inosilicate
- Comments
- from Vogt et al. (2002)
- Relevance
- impurity
- Arrangement
- unknown
- Mass fraction
- 1.0 $\pm$ 0.001
- Formula
- $(Fe^{2+}_x,Mn^{2+}_y,Mg_{1-x-y})_2.[SiO_3]_2 \ \ \ \ \ $ where $x=0-1, y=0-0.5$
- Chemical formula
- (Fe2+,Mn2+,Mg)2Si2O6
- Elemental formula
- (Fe2+)0-2 (Mn2+)0-1 (Mg)0-2 Si2 O6
- Isotope mixture type
- terrestrial abundance
- 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
- colorless, white, greenish white, yellowish green, yellow orange, green, gray, brown, dark brown, black
- Diaphaneity
- transparent to opaque
- Luster
- vitreous