LIVE REPORT! Gold and Silver Deposits in Colorado Symposium 2017 - last updated 5 minutes ago. Click here to watch.
Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Chromite

This page is currently not sponsored. Click here to sponsor this page.
Formula:
Fe2+Cr3+2O4
System:
Isometric
Colour:
Black
Lustre:
Resinous, Greasy, Metallic, Sub-Metallic, Dull
Hardness:
Member of:
Name:
Chromite was named in 1845 by Wilhelm Haidinger in allusion to its composition. The species was originally named fer chromate alumine by Louis Nicolas Vauquelin in 1798. Vauquelin was the discoverer of the element chromium.
Dimorph of:
Isostructural with:
Spinel Group. It apparently forms a complete solid solution series with many other members of the group, eg. in the Chromite-Hercynite Series, Chromite-Spinel Series, Chromite-Magnetite Series and the Chromite-Magnesiochromite Series. It is the iron analogue of Zincochromite, Cochromite, Manganochromite and Magnesiochromite and the Cr analogue of Hercynite, Coulsonite and Magnetite

It usually contains Mg, ferric iron [Fe(III)], Al and often Ti. "Ferritchromit", i.e. Fe(III) substitutions for Al and Cr, usually in grain rims, may give high total Fe contents and a false chromite identification. Of course, the definition requires dominant Fe(II)>Mg and Cr>Fe(III). (e.g. photo ID: 514894).

"Chromite" is commonly used for any Cr-rich mineral of the spinel group, particularly for the chromite-magnesiochromite series, and much of the mineral referred to as "chromite" in geological and petrological papers and mining statistics is usually Magnesiochromite. The Fe-dominant species - Chromite itself - can be FOUND, although uncommonly, in many "chromite" deposits, chromitite (rock name), and other "chromite"-bearing occurrences connected with hyperbasic rocks. As a rule of thumb, a member of the chromite-magnesiochromite series is twice as likely to be a magnesiochromite instead of a chromite. "Chromites" associated with olivine or serpentines, which are Mg-rich rocks, frequently have Mg-rich associated minerals. True chromite is common as inclusions in Diamonds from kimberlites (South Africa and Yakutia). Members of the spinel group may be enriched Cr and V in marbles (Slyudyanka), massive sulphide ores (Outokumpu) and also in some types of meteorites. In any case, "chromite" always needs ANALYTICAL CONFIRMATION. Note: Chromite, that is near end-member, has a higher specific gravity than near end-member magnesiochromite.


Classification of Chromite

Approved, 'Grandfathered' (first described prior to 1959)
First Published:
1845
4.BB.05

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
B : Metal: Oxygen = 3:4 and similar
B : With only medium-sized cations
7.2.3.3

7 : MULTIPLE OXIDES
2 : AB2X4
7.14.12

7 : Oxides and Hydroxides
14 : Oxides of Cr

Physical Properties of Chromite

Resinous, Greasy, Metallic, Sub-Metallic, Dull
Transparency:
Translucent, Opaque
Colour:
Black
Streak:
Brown
Hardness:
5½ on Mohs scale
Hardness:
VHN100=1278 - 1456 kg/mm2 - Vickers
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
Parting may develop along {111}
Fracture:
Irregular/Uneven, Hackly, Sub-Conchoidal
Comment:
Broken surfaces frequently have an angular granulated appearance.
Density:
4.5 - 4.8 g/cm3 (Measured)    5.12 g/cm3 (Calculated)

Optical Data of Chromite

Type:
Isotropic
RI values:
n = 2.08 - 2.16
Birefringence:
0.0
Max Birefringence:
δ = 0.000 - Isotropic minerals have no birefringence
Surface Relief:
Very High
Type:
Isotropic
Colour in reflected light:
Grey-white with brownish tint.
Internal Reflections:
Brownish red
Pleochroism:
Non-pleochroic

Chemical Properties of Chromite

Formula:
Fe2+Cr3+2O4
IMA Formula:
Fe2+Cr2O4
Idealised Formula:
FeCr2O4
Common Impurities:
Mg,Mn,Zn,Al,Ti

Crystallography of Chromite

Crystal System:
Isometric
Class (H-M):
m3m (4/m 3 2/m) - Hexoctahedral
Space Group:
Fd3m
Setting:
Fd3m
Cell Parameters:
a = 8.344 Å
Unit Cell V:
580.93 ų (Calculated from Unit Cell)
Z:
8
Morphology:
Octahedral crystals uncommon, modified by {001} at times. Rarely, crystals may show small dodecahedral faces, etc. Usually massive, fine granular to compact.
Twinning:
On {111}

Crystallographic forms of Chromite

Crystal Atlas:
Image Loading
Click on an icon to view
Chromite no.1 - Goldschmidt (1913-1926)
Chromite no.2 - Goldschmidt (1913-1926)
3d models and HTML5 code kindly provided by www.smorf.nl.

Toggle
Edge Lines | Miller Indicies | Axes

Transparency
Opaque | Translucent | Transparent

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

X-Ray Powder Diffraction

Powder Diffraction Data:
d-spacingIntensity
4.84 (10)
2.96 (30)
2.53 (100)
2.09 (20)
1.61 (40)
1.48 (50)
1.09 (10)
0.855 (10)
Comments:
ICDD 34-140 (synthetic). See also GSAM 85:195 (1962) natural material.

Occurrences of Chromite

Paragenetic Mode(s):

Type Occurrence of Chromite

Relationship of Chromite to other Species

Series:
Forms a series with Hercynite (see here)
Forms a series with Magnesiochromite (see here)
Forms a series with Magnetite (see here)
Member of:
Other Members of this group:
Cochromite(Co,Ni,Fe)(Cr,Al)2O4
CoulsoniteFe2+V3+2O4
CuprospinelCu2+Fe3+2O4
Filipstadite(Sb0.5Fe0.5)Mn2O4
FrankliniteZn2+Fe3+2O4
GahniteZnAl2O4
GalaxiteMn2+Al2O4
HercyniteFe2+Al2O4
JacobsiteMn2+Fe3+2O4
MagnesiochromiteMgCr2O4
MagnesiocoulsoniteMgV2O4
MagnesioferriteMgFe3+2O4
MagnetiteFe2+Fe3+2O4
ManganochromiteMn2+Cr2O4
Nichromite(Ni,Co,Fe)(Cr,Fe,Al)2O4
Qandilite(Mg,Fe3+)2(Ti,Fe3+,Al)O4
SpinelMgAl2O4
TrevoriteNi2+Fe3+2O4
UlvöspinelFe2TiO4
VuorelaineniteMn2+V3+2O4
XieiteFe2+Cr2O4
ZincochromiteZnCr2O4

Common Associates

Associated Minerals Based on Photo Data:
Serpentine Subgroup32 photos of Chromite associated with Serpentine Subgroup on mindat.org.
Chromian Clinochlore25 photos of Chromite associated with Chromian Clinochlore on mindat.org.
Uvarovite21 photos of Chromite associated with Uvarovite on mindat.org.
Grossular12 photos of Chromite associated with Grossular on mindat.org.
Olivine12 photos of Chromite associated with Olivine on mindat.org.
Antigorite11 photos of Chromite associated with Antigorite on mindat.org.
Magnetite11 photos of Chromite associated with Magnetite on mindat.org.
Phlogopite7 photos of Chromite associated with Phlogopite on mindat.org.
Mariinskite7 photos of Chromite associated with Mariinskite on mindat.org.
Stichtite6 photos of Chromite associated with Stichtite on mindat.org.

Related Minerals - Nickel-Strunz Grouping

4.BB.05Cochromite(Co,Ni,Fe)(Cr,Al)2O4
4.BB.05CoulsoniteFe2+V3+2O4
4.BB.05CuprospinelCu2+Fe3+2O4
4.BB.05Filipstadite(Sb0.5Fe0.5)Mn2O4
4.BB.05FrankliniteZn2+Fe3+2O4
4.BB.05GahniteZnAl2O4
4.BB.05GalaxiteMn2+Al2O4
4.BB.05HercyniteFe2+Al2O4
4.BB.05JacobsiteMn2+Fe3+2O4
4.BB.05ManganochromiteMn2+Cr2O4
4.BB.05MagnesiocoulsoniteMgV2O4
4.BB.05MagnesiochromiteMgCr2O4
4.BB.05MagnesioferriteMgFe3+2O4
4.BB.05MagnetiteFe2+Fe3+2O4
4.BB.05Nichromite(Ni,Co,Fe)(Cr,Fe,Al)2O4
4.BB.05Qandilite(Mg,Fe3+)2(Ti,Fe3+,Al)O4
4.BB.05SpinelMgAl2O4
4.BB.05TrevoriteNi2+Fe3+2O4
4.BB.05UlvöspinelFe2TiO4
4.BB.05VuorelaineniteMn2+V3+2O4
4.BB.05ZincochromiteZnCr2O4
4.BB.10HausmanniteMn2+Mn3+2O4
4.BB.10HetaeroliteZnMn2O4
4.BB.10HydrohetaeroliteZnMn2O4 · H2O
4.BB.10IwakiiteMn2+Fe3+2O4
4.BB.15MaghemiteFe3+2O3
4.BB.15TitanomaghemiteFe3+(Fe3+,Ti4+,Fe2+,◻)2O4
4.BB.20Tegengrenite(Mg,Mn2+)2Sb5+0.5(Mn3+,Si,Ti)0.5O4
4.BB.25XieiteFe2+Cr2O4

Related Minerals - Hey's Chemical Index of Minerals Grouping

7.14.1EskolaiteCr2O3
7.14.2BracewelliteCrO(OH)
7.14.3GrimaldiiteCrO(OH)
7.14.4GuyanaiteCrO(OH)
7.14.5YimengiteK(Cr,Ti,Fe,Mg)12O19
7.14.6Mathiasite(K, Ba, Sr)(Zr, Fe)(Mg,Fe)2 (Ti,Cr,Fe)18O38
7.14.7McconnelliteCuCrO2
7.14.8RedledgeiteBa(Ti4+6Cr3+2)O16
7.14.9HawthorneiteBaMgTi3Cr4Fe2+2Fe3+2O19
7.14.10ZincochromiteZnCr2O4
7.14.11Wattersite(Hg+2)2Hg2+(CrO4)O2
7.14.13MagnesiochromiteMgCr2O4

Related Minerals - Dana Grouping (8th Ed.)

7.2.3.1MagnesiochromiteMgCr2O4
7.2.3.2ManganochromiteMn2+Cr2O4
7.2.3.4Nichromite(Ni,Co,Fe)(Cr,Fe,Al)2O4
7.2.3.5Cochromite(Co,Ni,Fe)(Cr,Al)2O4
7.2.3.6ZincochromiteZnCr2O4

Synonyms of Chromite

Other Language Names for Chromite

Varieties of Chromite

Aluminian Chromite

An aluminian variety of Chromite. Cr:Al from 3:1 to 1:1

Alumoberezovite

A magnesian aluminian Chromite

Berezovskite

A Magnesian Chromite

Chromferrit

Ferrian Chromite

A member of Chromite-Magnetite Series - a ferrian variety of Chromite with Fe3+ contents 0,10-0,50 apfu.

Ferrichromite

A member of Chromite-Magnetite Series - a ferrian variety of Chromite with Fe3+ contents 0,50-1 apfu.

Titaniferous Chromite

A titanium-bearing variety of chromite.

Fluorescence of Chromite

Not fluorescent in UV

Other Information

Notes:
Some are weakly magnetic due to zones of magnetite composition, etc.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Industrial Uses:
Major ore source for chromium.

Chromite in petrology

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

References for Chromite

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Vauqueline (1800), Bull. soc. philom.: 55: 57.
Pemberton, H. (1891), Chromite: Chem. News: 63: 241.
Simpson (1920), Mineralogical Magazine: 19: 99 (as Beresofite).
Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged: 709-712.
Bliss, N.W. and MacLean, W.H. (1975) The paragenesis of zoned chromite from central Manitoba. Geochimica et Cosmochimica Acta: 39: 973-990.
Da Silva, E.G., Abras, A., and Sette Camara, A.O.R. (1976) Mössbauer effect study of cation distribution in natural chromites. Journal of Applied Physics: 12: 783-785.
Fatseas, G.A., Dormann, J.L., and Blanchard, H. (1976) Study of the Fe 3+ / Fe 2+ ratio in natural chromites (Fe x Mg 1-x)(Cr 1-y-x Fe y Al z)O4. Journal of Physics: 12: 787-792.
Da Silva, E.G., Abras, A., and Speziali, L. (1980) Mössbauer effect study of cation distribution in natural chromites of Brazilian and Philippine origin. Journal of Applied Physics: 12: 389-392.
Osborne, M.D., Fleet, M.E., and Bancroft, G.M. (1981) Fe 2+ - Fe 3+ ordering in chromite and Cr-bearing spinels. Contributions to Mineralogy and Petrology: 77: 251-255.
Mitra, S., PAl, T., and Pal, T. (1991) Petrogenic implication of the Mössbauer hyperfine parameters of Fe 3+-chromites from Sukinda (India) ultramafites. Mineralogical Magazine: 55(4): 535:542.
Chen, Y.L., Xu, B.F., Chen, J.G., and ge, Y.Y. (1992) Fe 2+ - Fe 3+ ordered distribution in chromite spinels. Physics and Chemistry of Minerals: 19(4): 255-259.
Leblanc, M. and Ceuleneer, G. (1992) Chromite crystallisation in multicelular magma flow: evidence from a chromitite dike in the Oman ophiolite. Lithos: 27: 231-257.
Canadian Mineralogist (1994): 32: 729-746.
Zhou, Mei-Fu, Robinson, P.T., and Bai, W.J. (1994) Formartion of podiform chromitites by melt/rock interaction in the upper mantle. Mineral. Deposita: 29: 98-101.
Zhou, Mei-Fu, Robinson, P.T., Malpas, J., and Li, Z. (1996) Podiform chromitites in the Luobusa ophiolite (southern Tibet): implications for melt-rock interaction and chromite segregation in the upper mantle. Journal of Petrology: 37: 3-21.
Figueiras, J. and Waerenborgh, J.C. (1997) Fully oxidized chromite in the Serra Alta (South Portugal) quartzites: chemical and structural characterization and geological implications. Mineralogical Magazine: 61: 627-638.
Zhou, Mei-Fu and Robnson, P.T. (1997) Origin and tectonic environment of podiform chromite deposits. Economic geology: 92: 259-262.
Zhou, Mei-Fu, Sun, Min, Keays, R.R., and Kerrich, R.W. (1998) Controls on platinum-group elemental distributions of podiform chromitites: a case study of high-Cr and high-Al chromitites from Chinese orogenic belts. Geochimica et Cosmochimica Acta: 62: 677-688.
Barnes, S.J. (2000) Chromite in komatiites. II. Modification during greenschist to mid-amphibolite facies metamorphism. Journal of Petrology: 41: 387-409.
Salviulo, G., Carbonin, S., and Della Giusta, A. (2000) Powder and single-crystal X-ray structural refinements on a natural chromite: dependence of site occupancies on experimental strategies. Materials Science Forum: 321-324: 46-52.
Papike, J.J., Karner, J.M., and Shearer, C.K. (2004) Comparative planetary mineralogy: V/(Cr+Al) systematics in chromite as an indicator of relative oxygen fugacity. American Mineralogist: 89: 1557-1560.
Mosier, D.L., Singer, D.A., Moring, B.C., and Galloway, J.P., (2012), Podiform chromite deposits—database and grade and tonnage models: U.S. Geological Survey Scientific Investigations Report 2012–5157, 45 p. and database.

Internet Links for Chromite

mindat.org URL:
https://www.mindat.org/min-1036.html
Please feel free to link to this page.

Localities for Chromite

Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2017, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: July 21, 2017 21:29:24
Go to top of page