Mindat Logo
Home Page Log In Message Board The Mindat Directory
Register Search Pages Chat Now! (2 online) Mindat Auctions

Enstatite

Big Photo

Summit Rock, Klamath Co., Oregon, USA
© DM06

Show Enstatite Photos (57)
Formula:
Mg
 
2
[SiO
 
3
]
 
2
System:OrthorhombicColour:White, yellowish green, ...
Lustre:Vitreous, PearlyHardness:5 - 6
Name:From the Greek enstates - "opponent" for refractory nature under blowpipe flame.
Dimorph of:Clinoenstatite


Enstatite Group. Enstatite-Ferrosilite Series.

Classification of Enstatite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:8/F.02-10
Nickel-Strunz 10th (pending) edition ID:9.DA.05

9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si2O6; pyroxene family
Dana 8th edition ID:65.1.2.1

65 : INOSILICATES Single-Width,Unbranched Chains,(W=1)
1 : Single-Width Unbranched Chains, W=1 with chains P=2
Hey's CIM Ref.:14.4.2

14 : Silicates not Containing Aluminum
4 : Silicates of Mg
mindat.org URL:http://www.mindat.org/min-1384.html
Please feel free to link to this page.

Occurrences of Enstatite

Geological Setting:Magmatic mafic rocks

Physical Properties of Enstatite

Lustre:Vitreous, Pearly
Diaphaneity (Transparency):Translucent, Opaque
Comment:Pearly on cleavage
Colour:White, yellowish green, brown, greenish white or grey, olive-green
Streak:Grey to white
Hardness (Mohs):5 - 6
Tenacity:Brittle
Cleavage:Distinct/Good
Good on {210}
Parting:on {100} and {010}
Fracture:Irregular/Uneven
Density (measured):3.2 - 3.9 g/cm3
Density (calculated):3.189 g/cm3

Crystallography of Enstatite

Crystal System:Orthorhombic
Class (H-M):mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:Pbca (P21/b 21/c 21/a)
Cell Parameters:a = 18.23Å, b = 8.84Å, c = 5.19Å
Ratio:a:b:c = 2.062 : 1 : 0.587
Unit Cell Volume:V 836.39 ų (Calculated from Unit Cell)
Z:8
Morphology:Prismatic crystals
Twinning:Simple and lamellar on {100}
Crystal Atlas:
Image Loading
Click on an icon to view
Enstatite no.12 - Goldschmidt (1913-1926)
Enstatite no.67 - Goldschmidt (1913-1926)

About Crystal Atlas

You may need to scroll this box using your mouse to view the full instructions.

The mindat.org Crystal Atlas allows you to view a selection of crystal drawings of real and idealised crystal forms for this mineral and, in certain cases, 3d rotating crystal objects. You need Java to see these. You can download Java for free - click here to download Java

The 3d models and java code are kindly provided by www.smorf.nl. You can control the movement of the models by holding down the left mouse-button over the 3d model and moving your mouse. Keyboard controls are:

: default positions
t/T: decrease/increase transparency x/X: next/previous texture
b/B: next/previous background w: toggle wireframe
s: toggle sticks m: toggle miller indices
k: toggle crystallographic axes =/-: zoom in/out
r: stop/start rotation 1/2/3


Note: You will not be able to switch between different crystal models using the Opera 8.5x web browser due to a bug in Opera - you need to use either Firefox or Internet Explorer 6/7 or Opera 9.
X-Ray Powder Diffraction:
Image Loading

Radiation - Copper Kα
Data Set:
Horizontal Axis: ° to ° Vertical Axis: % Source Data: Filtered Data: Peaks:
Data courtesy of RRUFF project at University of Arizona, used with permission.

Optical Data of Enstatite

Type:Biaxial (+)
RI values: nα = 1.650 - 1.668 nβ = 1.652 - 1.673 nγ = 1.659 - 1.679
2V:Measured: 54° to 90°, Calculated: 58° to 86°
Maximum Birefringence:δ = 0.009 - 0.011

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Moderate
Dispersion:r < v weak

Chemical Properties of Enstatite

Formula:
Mg
 
2
[SiO
 
3
]
 
2
Essential elements:Mg, O, Si
All elements listed in formula:Mg, O, Si
Common Impurities:Fe,Ca,Al,Co,Ni,Mn,Ti,Cr,Na,K

Relationship of Enstatite to other Species

Series:Forms a series with Ferrosilite (see here)
Related Minerals - Nickel-Strunz Grouping):
9.DA.05Donpeacorite
(Mn
2+
 
,Mg)Mg[SiO
 
3
]
 
2
9.DA.05Ferrosilite
Fe
 
2
[SiO
 
3
]
 
2
9.DA.05Akimotoite
(Mg,Fe
2+
 
)SiO
 
3
9.DA.10Clinoenstatite
Mg
 
2
[Si
 
2
O
 
6
]
9.DA.10Clinoferrosilite
Fe
2+
 
(Fe
2+
 
,Mg)[Si
 
2
O
 
6
]
9.DA.10Kanoite
Mn
2+
 
(Mg,Mn
2+
 
)[Si
 
2
O
 
6
]
9.DA.10Pigeonite
(Mg,Fe
2+
 
,Ca)(Mg,Fe
2+
 
)[Si
 
2
O
 
6
]
9.DA.15Augite
(Ca,Na)(Mg,Fe
2+
 
,Al,Fe
3+
 
,Ti)[(Si,Al)
 
2
O
 
6
]
9.DA.15Diopside
CaMg[Si
 
2
O
 
6
]
9.DA.15Esseneite
CaFe
3+
 
[AlSiO
 
6
]
9.DA.15Hedenbergite
CaFe
2+
 
[Si
 
2
O
 
6
]
9.DA.15Johannsenite
CaMn
2+
 
[Si
 
2
O
 
6
]
9.DA.15Petedunnite
Ca(Zn,Mn
2+
 
,Mg,Fe
2+
 
)[Si
 
2
O
 
6
]
9.DA.20Aegirine-augite
(Na,Ca)(Fe,Fe,Mg,Al)Si
 
2
O
 
6
9.DA.20Omphacite
(Ca,Na)(Mg,Al)[Si
 
2
O
 
6
]
9.DA.25Aegirine
NaFe
3+
 
[Si
 
2
O
 
6
]
9.DA.25Jadeite
Na(Al,Fe
3+
 
)[Si
 
2
O
 
6
]
9.DA.25Jervisite
(Na,Ca,Fe
2+
 
)(Sc,Mg,Fe
2+
 
)[Si
 
2
O
 
6
]
9.DA.25Kosmochlor
NaCr[Si
 
2
O
 
6
]
9.DA.25Namansilite
NaMn
3+
 
[Si
 
2
O
 
6
]
9.DA.25Natalyite
Na(V
3+
 
,Cr)[Si
 
2
O
 
6
]
9.DA.30Spodumene
LiAl[Si
 
2
O
 
6
]
Related Minerals - Hey's Index Grouping:
14.4.1Forsterite
Mg
 
2
[SiO
 
4
]
14.4.3Clinoenstatite
Mg
 
2
[Si
 
2
O
 
6
]
14.4.4Chrysotile
Mg
 
3
Si
 
2
O
 
5
(OH)
 
4
14.4.5Clinochrysotile
14.4.6Orthochrysotile
14.4.7Parachrysotile
14.4.8Lizardite
Mg
 
3
[(OH)
 
4
|Si
 
2
O
 
5
]
14.4.9Talc
Mg
 
3
Si
 
4
O
 
10
(OH)
 
2
14.4.10Spadaite
MgSiO
 
2
(OH)
 
2
·H
 
2
O
14.4.11Sepiolite
Mg
 
4
Si
 
6
O
 
15
(OH)
 
2
·6H
 
2
O
14.4.12Loughlinite
Na
 
2
Mg
 
3
Si
 
6
O
 
16
·8H
 
2
O
14.4.13Eifelite
KNa
 
3
Mg
 
4
Si
 
12
O
 
30
14.4.14Stevensite
(Ca,Na)
 
x
Mg
 
3
Si
 
4
O
 
10
(OH)
 
2
14.4.15Antigorite
(Mg,Fe
2+
 
)
 
3
[(OH)
 
4
|Si
 
2
O
 
5
]
14.4.16 Magnesio-anthophyllite

Other Names for Enstatite

Synonyms:
AmblystegiteChladniteEnstaditeFiciniteO-enstatite
OrthobronziteOrthoenstatitePaulitePeckhamiteProtobastite
SheparditeShepardite (of Rose)Victorite
German names:
AmblystegitChladnitCladnitEnstaditEnstatit
FicinitO-enstatitOrthobronzitOrthoenstatitPaulit
PeckhamitProtobastitSheparditVictorit
Russian names:
Энстатит
Spanish names:
AmblystegitaChladnitaEnstaditaEnstatitaFicinita
OrthobronzitaOrthoenstatitaPaulitaPeckhamitaProtobastita
SheparditaVictorita
Varieties:
BronziteLime-BronziteVanadinbronzite

Other Information

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

References for Enstatite

Reference List: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. 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.

Zeitschrift für Kristallographie (1986): 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. Pysics 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 exansion 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. (2002a) 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. (2002b) Mixing properties of the enstatite-ferrosilite solid solution: II A microscopic perspective. Eurpean 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 Enstatite

Search Engines:
  • Look for Enstatite on Google
  • Look for Enstatite images on Google
    • External Links:
  • Look for Enstatite on Webmineral
  • Look for Enstatite on Athena Mineralogy
  • Look for Enstatite on Wikipedia
  • Look for Enstatite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Enstatite in the Natural History Museum (London) online catalogue
  • Enstatite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • Buy from David K Joyce minerals
  • High-end worldwide specimens & outstanding customer service
  • Fabre Minerals - search for Enstatite specimens
  • Wendel Minerals - Auktion & Shop
  • Rare and Unusual minerals at Mineralogical Research Company
  • Wilensky Fine Minerals
  • Top quality minerals from Kristalle of California
  • Fine Minerals from Dan Weinrich Minerals
  • e-Rocks - Mineral Auctions and Sales
  • Find Enstatite on www.crystalclassics.co.uk
  • Lapis Mineral Magazin
  • Search for Enstatite at Thames Valley Minerals
    • Jobs:
  • Mining & Geology Jobs

    • Page Sponsor

    Sponsorship:This page is currently not sponsored. Click here to find out how you can sponsor this page.

    Localities for Enstatite

    Show Locality List (350 Items)
    The 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.
    These maps work faster with Firefox!
    Mineral and/or Locality
    Google
     
    www.mindat.org Web
    Copyright © Jolyon & Ida Ralph 1993-2008. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. If you would like to add information to improve the quality of our database, then click here to register.