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White, yellowish green, brown, greenish white or grey, olive-green
Vitreous, Pearly
5 - 6
Specific Gravity:
3.2 - 3.9
Crystal System:
From the Greek enstates - "opponent" for refractory nature under blowpipe flame.
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Classification of EnstatiteHide

Approved, 'Grandfathered' (first described prior to 1959)

9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si2O6; pyroxene family

65 : INOSILICATES Single-Width,Unbranched Chains,(W=1)
1 : Single-Width Unbranched Chains, W=1 with chains P=2

14 : Silicates not Containing Aluminum
4 : Silicates of Mg

Physical Properties of EnstatiteHide

Vitreous, Pearly
Translucent, Opaque
Pearly on cleavage
White, yellowish green, brown, greenish white or grey, olive-green
Grey to white
5 - 6 on Mohs scale
Good on {210}
on {100} and {010}
3.2 - 3.9 g/cm3 (Measured)    3.189 g/cm3 (Calculated)

Optical Data of EnstatiteHide

Biaxial (+)
RI values:
nα = 1.650 - 1.668 nβ = 1.652 - 1.673 nγ = 1.659 - 1.679
Measured: 54° to 90°, Calculated: 58° to 86°
Max Birefringence:
δ = 0.009 - 0.011
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
r < v weak

Chemical Properties of EnstatiteHide

Common Impurities:

Crystallography of EnstatiteHide

Crystal System:
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Cell Parameters:
a = 18.23 Å, b = 8.84 Å, c = 5.19 Å
a:b:c = 2.062 : 1 : 0.587
Unit Cell V:
836.39 ų (Calculated from Unit Cell)
Prismatic crystals
The often reported "Simple and lamellar twinning on {100}" is no twinning (the symmetry plane is part of the crystal structure). Twinning may be confused with exsolution lamellae.

Crystallographic forms of EnstatiteHide

Crystal Atlas:
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Click on an icon to view
Enstatite no.12 - Goldschmidt (1913-1926)
Enstatite no.67 - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by

Edge Lines | Miller Indicies | Axes

Opaque | Translucent | Transparent

Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation

X-Ray Powder DiffractionHide

Image Loading

Radiation - Copper Kα
Data Set:
Data courtesy of RRUFF project at University of Arizona, used with permission.

Synonyms of EnstatiteHide

Other Language Names for EnstatiteHide

Varieties of EnstatiteHide

BronziteA ferroan variety of enstatite
Lime-BronziteA Calcian Bronzite
VanadinbronziteA vanadium-bearing variety of enstatite.
Originally reported from Bracco, Genova Province, Liguria, Italy.

Relationship of Enstatite to other SpeciesHide

Other Members of this group:
FerrosiliteFeSiO3Orth. mmm (2/m 2/m 2/m) : Pbca
Forms a series with:

Common AssociatesHide

Associated Minerals Based on Photo Data:
Pseudobrookite31 photos of Enstatite associated with Pseudobrookite on
Ilmenite21 photos of Enstatite associated with Ilmenite on
Tridymite21 photos of Enstatite associated with Tridymite on
Hematite19 photos of Enstatite associated with Hematite on
Zircon9 photos of Enstatite associated with Zircon on
Armalcolite-Pseudobrookite Series8 photos of Enstatite associated with Armalcolite-Pseudobrookite Series on
Diopside8 photos of Enstatite associated with Diopside on
Fluoro-edenite4 photos of Enstatite associated with Fluoro-edenite on
Sanidine4 photos of Enstatite associated with Sanidine on
Fluorapatite4 photos of Enstatite associated with Fluorapatite on

Related Minerals - Nickel-Strunz GroupingHide

9.DA.05FerrosiliteFeSiO3Orth. mmm (2/m 2/m 2/m) : Pbca
9.DA.10KanoiteMn2+(Mg,Mn2+)Si2O6Mon. 2/m : P21/b
9.DA.10Pigeonite(CaxMgyFez)(Mgy1Fez1)Si2O6Mon. 2/m : P21/b
9.DA.15Augite(CaxMgyFez)(Mgy1Fez1)Si2O6Mon. 2/m : B2/b
9.DA.15DiopsideCaMgSi2O6Mon. 2/m : B2/b
9.DA.15EsseneiteCaFe3+[AlSiO6]Mon. 2/m : B2/b
9.DA.15HedenbergiteCaFe2+Si2O6Mon. 2/m : B2/b
9.DA.15JohannseniteCaMn2+Si2O6Mon. 2/m : B2/b
9.DA.15DavisiteCaScAlSiO6Mon. 2/m : B2/b
9.DA.15KushiroiteCaAl[AlSiO6]Mon. 2/m : B2/b
9.DA.15GrossmaniteCaTi3+ AlSiO6Mon. 2/m : B2/b
9.DA.20Aegirine-augite(NaaCabFe2+cMgd)(Fe3+eAlfFe2+gMgh)Si2O6Mon. 2/m : B2/b
9.DA.20Omphacite(NaaCabFe2+cMgd)(AleFe3+fFe2+gMgh)Si2O6Mon. 2/m
9.DA.25AegirineNaFe3+Si2O6Mon. 2/m : B2/b

Related Minerals - Dana Grouping (8th Ed.)Hide mmm (2/m 2/m 2/m) : Pbca,Mg)Mg[SiO3]2Orth.

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

14.4.1ForsteriteMg2SiO4Orth. mmm (2/m 2/m 2/m)
14.4.5ClinochrysotileMon. 2/m
14.4.9TalcMg3Si4O10(OH)2Tric. 1 : P1
14.4.10SpadaiteMgSiO2(OH)2 · H2O (?)
14.4.11SepioliteMg4(Si6O15)(OH)2 · 6H2OOrth. mmm (2/m 2/m 2/m) : Pnna
14.4.12LoughliniteNa2Mg3Si6O16 · 8H2OOrth.
14.4.15AntigoriteMg3(Si2O5)(OH)4Mon. m : Bm
14.4.16 Magnesio-anthophyllite☐{Mg2}{Mg5}(Si8O22)(OH)2

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Enstatite in petrologyHide

An essential component of (items highlighted in red)
Common component of (items highlighted in red)

References for EnstatiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Klaproth, M.H. (1810) Chemische Untersuchung des Bronzits, Beiträge zur chemischen Kenntniss der Mineralkörper, Fünfter Band, Rottmann Berlin, 32-36.
Johansson, K. (1894) Zeits. Kryst. Min., vol. 23, p. 152.
Bowman, H.L. (1900) On a rhombic pyroxene from South Africa. Mineralogical Magazine, vol. 12, n° 58, 349-358.
Henry, N.F.M. (1935) Some data on the iron-rich hypersthenes. Mineralogical Magazine, vol. 24, n° 151, 221-226.
Walls, R. (1935) A critical review of the data for a revision of the enstatite-hypersthene series. Mineralogical Magazine, vol. 24, n° 150, 165-172.
Morimoto, N. and Koto, K. (1969) The crystal structure of orthoenstatite. Zeitschrift für Kristallographie: 129: 65-83.
Anastasiou, P. and Seifert, F. (1972) Solid solubility of Al2O3 in enstatite at high temperatures and 1-5 kb water pressure. Contributions to Mineralogy and Petrology: 34: 272-287.
Arima, M. and Onuma, K. (1977) The solubility of alumina in enstatite and the phase equilibria in the join MgSiO3-MgAl2SiO6 at 10-25 kbar. Contributions to Mineralogy and Petrology: 61: 251-265.
Hawthorne, F.C. and Ito, J. (1977) Synthesis and crystal structure refinement of transition-metal orthopyroxenes. I: orthoenstatite and (Mg,Mn,Co) orthopyroxene. The Canadian Mineralogist: 15: 321-338.
Weidner, D.J., Wang, H., and Ito, J. (1978) Elasticity of orthoenstatite. Physics of the Earth and Planetary Interiors 17: 7-13.
Ralph, R.L. and Ghose, S. (1980) Enstatite, Mg2Si2O6: compressibility and crystal structure at 21 kbar (abs.). Eos: 61: 409.
Ohashi, Y. (1984) Polysynthetically-twinned structures of enstatite and wollastonite. Physics and Chemistry of Minerals: 10: 217-229.
Ghose, S., Schomaker, V., and Mcmullan, R.K. (1986) Enstatite, Mg2Si2O6 - a neutron-diffraction refinement of the crystal structure and a rigid-body analysis of the thermal variation. Zeitschrift für Kristallographie: 176: 159.
Duffy, T.S. and Vaughan, M.T. (1988) Elasticity of enstatite and its relationship to crystal structure. Journal of Geophysical Research: 93: 383-391.
Angel, R.J. and Hugh-Jones, D.A. (1994) Equation of state and thermodynamic properties of enstatite pyroxenes. Journal of Geophysical Research: 99: 19777-19783.
Hugh-Jones, D.A. and Angel, R.J. (1994) A compressional study of MgSiO3 orthoenstatite up to 8.5 GPa. American Mineralogist: 79: 405-410.
Yang, H. and Ghose, S. (1994) High-temperature single-crystal X-ray diffraction studies of the ortho-proto phase transition in enstatite, Mg2Si2O6 at 1360 K. Physics and Chemistry of Minerals: 22: 300-310.
Zhao, Y., Schiferl, D., and Shankland, T.J. (1995) A high P-T single-crystal X-ray diffraction study of thermoelasticity of MgSiO3 orthoenstatite. Physics and Chemistry of Minerals: 22: 393-398.
Flesch, L.M., Li., B., and Liebermann, R.C. (1998) Sound velocities of polycrystalline MgSiO3-orthopyroxene to 10 GPa at room temperature. American Mineralogist: 83: 444-450.
Jackson, J.M., Sinogeikin, S.V., and Bass, J.D. (1999) Elasticity of MgSiO3 orthoenstatite. American Mineralogist: 84: 677-680.
Jackson, J.M., Palko, J., Sinogeikin, S.V., Bass, J.D., Andrault, D., and Zha, C. (2001) High-temperature single-crystal elasticity and thermal expansion of orthoenstatite. Eos (Fall Meeting Supplement), Abstract T31C-0853.
Angel, R.J. and Jackson, M.J. (2002) Elasticity and equation of state of orthoenstatite, MgSiO3. American Mineralogist: 87: 558-561.
Tarantino, S.C., Domeneghetti, M.C., Carpenter, M.A., Shaw, C.J.S., and Tazzoli, V. (2002) Mixing properties of the enstatite-ferrosilite solid solution: I. A macroscopic perspective. European Journal of Mineralogy: 14: 525-536.
Tarantino, S.C., Boffa Ballaran, T., Carpenter, M.A., Domeneghetti, M.C., and Tazzoli, V. (2002) Mixing properties of the enstatite-ferrosilite solid solution: II A microscopic perspective. European Journal of Mineralogy: 14: 537-547.
Lin, C.C. (2003) Pressure-induced metastable phase transition in orthoenstatite (MgSiO3) at room temperature: a Raman spectroscopic study. Journal of Solid State Chemistry: 174: 403-411.
Jackson, J.M., Sinogeikin, S.V., Carpenter, M.A., and Bass, J.D. (2004) Novel phase transition in orthoenstatite. American Mineralogist: 89: 239-245.
Kung, J., Li, B.S., Uchida, T., Wang, Y.B., Neuville, D., and Liebermann, R.C. (2004) In situ measurements of sound velocities and densities across the orthopyroxene - high-pressure clinopyroxene transition in MgSiO3 at high-pressure. Physics of the Earth and Planetary Interiors: 147: 27-44.
Nestola, F., Gatta, G.D., and Ballaran, T.B. (2006) The effect of Ca substitution on the elastic and structural behavior of orthoenstatite. American Mineralogist: 91: 809-815.

Internet Links for EnstatiteHide

Localities for EnstatiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListShow

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