Mineral phase
- IMA name
- Enstatite
- Class
- silicate mineral
- Compound type
- inosilicate
- Comments
- Enstatite: name by extension of $(Fe,Mg)_2Si_2O6$ in the range Fe=0-10%
- Formula
- $Mg_2.[SiO_3]_2$
- Chemical formula
- Mg2Si2O6
- Elemental formula
- Mg2 Si2 O6
- Isotope mixture type
- terrestrial abundance
- Composition comments
- Common substitution: $Fe^{2+}$, $Mn^{2+}$ - Common impurities: $Fe^{3+}$, Al, Ca, Na, K, Co, Ni, Mn, Ti, Cr
- Oxides
-
Formula $MgO$ $SiO_{2}$ Mass fraction (%) 40.15 59.85
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
- 65.01.02.01
- Phase type
- crystalline
- Crystal system
- orthorhombic
- Crystal class
- dipyramidal
- Crystal class symbol
- mmm (D2h)
- Crystal spacegroup
- Pbca
- Molar mass
- 200.78 $g/mol$
- Density
- 3.1 - 3.3 $g/cm^3$
- State NTP
- solid
- Refringence type
- biaxial
- Refringence sign
- positive
- Birefringence
- 0.009 - 0.011
- Refraction index $n_{\alpha}$
- 1.650 - 1.668
- Refraction index $n_{\beta}$
- 1.652 - 1.673
- Refraction index $n_{\gamma}$
- 1.659 - 1.679
- Dispersion V
- weak to moderate (r < v)
- Pure color
- white
- Color
- white, yellowish green, brown, greenish white, gray
- Diaphaneity
- translucent to opaque
- Luster
- vitreous