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About EskolaiteHide

Professor Pentti Eskola
8 - 8½
Specific Gravity:
Crystal System:
Member of:
Named by Olavi Kouvo and Yrjö Vuorelained in 1958 in honor of Pentti Eelis Eskola (8 January 1883, Honkilahti, Finland – 6 December 1964, Helsinki, Finland), geologist at the University of Helsinki, Helsinki, Finland. He did pioneering work on metamorphic rocks and won several international awards including the 1958 Wollaston medal.
Hematite Group.
The chromium analogue of Corundum, Hematite, and Karelianite.

Classification of EskolaiteHide

Approved, 'Grandfathered' (first described prior to 1959)
First Published:

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
C : Metal: Oxygen = 2: 3,3: 5, and similar
B : With medium-sized cations

3 : A2X3

7 : Oxides and Hydroxides
14 : Oxides of Cr

Physical Properties of EskolaiteHide

Translucent, Opaque
8 - 8½ on Mohs scale
5.18 g/cm3 (Measured)    5.20 g/cm3 (Calculated)

Optical Data of EskolaiteHide

Colour in reflected light:
Internal Reflections:
Emerald green
In fragment / grain edges emerald green to olive green.
In polished sections, not pleochroic.

Chemical Properties of EskolaiteHide

Common Impurities:

Crystallography of EskolaiteHide

Crystal System:
Cell Parameters:
a = 4.95 Å, c = 13.58 Å
a:c = 1 : 2.743
Unit Cell V:
288.16 ų (Calculated from Unit Cell)
Hexagonal prisms and plates. {11-20}, {0001}, {11-23}, {10-11}.

X-Ray Powder DiffractionHide

Powder Diffraction Data:
3.630 Å(96)
2.665 Å(97)
2.479 Å(94)
2.174 Å(48)
1.8146 Å(58)
1.6746 Å(100)
1.4331 Å(47)

Type Occurrence of EskolaiteHide

General Appearance of Type Material:
Well developed hexagonal prisms 1-5 mm.
Geological Setting of Type Material:
Chromium-bearing tremolite skarn.
Kouvo, O., Vuorelainen, Y. (1958) Eskolaite, a new chromium mineral. American Mineralogist: 43: 1098-1106.

Other Language Names for EskolaiteHide

Simplified Chinese:绿铬矿

Relationship of Eskolaite to other SpeciesHide

Member of:
Other Members of this group:
CorundumAl2O3Trig. 3m (3 2/m) : R3c
HematiteFe2O3Trig. 3m (3 2/m) : R3c
TistariteTi3+2O3Trig. 3m (3 2/m) : R3c
Forms a series with:

Common AssociatesHide

Associated Minerals Based on Photo Data:
2 photos of Eskolaite associated with ChalcopyriteCuFeS2
1 photo of Eskolaite associated with McconnelliteCuCrO2

Related Minerals - Nickel-Strunz GroupingHide

4.CB.05BrizziiteNaSb5+O3Trig. 3 : R3
4.CB.05CorundumAl2O3Trig. 3m (3 2/m) : R3c
4.CB.05Ecandrewsite(Zn,Fe2+,Mn2+)TiO3Trig. 3 : R3
4.CB.05GeikieliteMgTiO3Trig. 3 : R3
4.CB.05HematiteFe2O3Trig. 3m (3 2/m) : R3c
4.CB.05IlmeniteFe2+TiO3Trig. 3 : R3
4.CB.05PyrophaniteMn2+TiO3Trig. 3 : R3
4.CB.05Unnamed (Auroantimonate)AuSbO3
4.CB.05TistariteTi3+2O3Trig. 3m (3 2/m) : R3c
4.CB.10AvicenniteTl2O3Iso. m3 (2/m 3) : Ia3
4.CB.10BixbyiteMn3+2O3Iso. m3 (2/m 3) : Ia3
4.CB.15Armalcolite(Mg,Fe2+)Ti2O5Orth. mmm (2/m 2/m 2/m)
4.CB.15PseudobrookiteFe2TiO5Orth. mmm (2/m 2/m 2/m)
4.CB.20Zincohögbomite-2N2S[(Zn,Al,Fe2+)3(Al,Fe3+,Ti)8O15(OH)]2Hex. 6mm : P63mc
4.CB.20Zincohögbomite-2N6S[(Zn,Mg)7(Al,Fe3+,Ti)16O31(OH)]2Hex. 6mm : P63mc
4.CB.20Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6Trig. 3m (3 2/m) : R3m
4.CB.20Magnesiohögbomite-2N3S[(Mg,Fe2+,Zn)4(Al,Ti,Fe3+)10O19(OH)]2Trig. 3m (3 2/m) : P3 1m
4.CB.20Magnesiohögbomite-2N2S[(Mg,Fe2+)3[Al7(Ti,Fe3+)]O15(OH)]2Hex. 6mm : P63mc
4.CB.20Ferrohögbomite-6N12S[(Fe2+,Mg,Zn)5(Al,Ti,Fe3+)12O23(OH)]6Trig. 3m (3 2/m) : R3m
4.CB.25KleberiteFeTi6O11(OH)5Mon. 2/m : P21/b
4.CB.30OxyvaniteV3+2V4+O5Mon. 2/m : B2/b
4.CB.40RinmaniteZn2Sb2Mg2Fe4O14(OH)2Hex. 6 : P63
4.CB.40IseiteMn2Mo3O8Hex. 6mm : P63mc
4.CB.40MajindeiteMg2Mo3O8Hex. 6mm : P63mc
4.CB.45ClaudetiteAs2O3Mon. 2/m
4.CB.45StibioclaudetiteAsSbO3Mon. 2/m : P21/m
4.CB.50ArsenoliteAs2O3Iso. m3m (4/m 3 2/m) : Fd3m
4.CB.50SenarmontiteSb2O3Iso. m3m (4/m 3 2/m) : Fd3m
4.CB.55ValentiniteSb2O3Orth. mmm (2/m 2/m 2/m) : Pccn
4.CB.60BismiteBi2O3Mon. 2/m : P21/b
4.CB.70SilléniteBi12SiO20Iso. 2 3 : I2 3
4.CB.75KyzylkumiteV3+Ti2O5(OH)Mon. 2/m : P21/b

Related Minerals - Dana Grouping (8th Ed.)Hide 3m (3 2/m) : R3c 3m (3 2/m) : R3c

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

7.14.2BracewelliteCrO(OH)Orth. mmm (2/m 2/m 2/m)
7.14.6Mathiasite(K, Ba, Sr)(Zr, Fe)(Mg,Fe)2 (Ti,Cr,Fe)18O38Trig.
7.14.9HawthorneiteBaMgTi3Cr4Fe2+2Fe3+2O19Hex. 6/mmm (6/m 2/m 2/m) : P63/mmc
7.14.11Wattersite(Hg+2)2Hg2+(CrO4)O2Mon. 2/m : B2/b
7.14.12ChromiteFe2+Cr3+2O4Iso. m3m (4/m 3 2/m) : Fd3m
7.14.13MagnesiochromiteMgCr2O4Iso. m3m (4/m 3 2/m) : Fd3m

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.

References for EskolaiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Kouvo, O., Vuorelainen, Y. (1958) Eskolaite, a new chromium mineral. American Mineralogist: 43: 1098-1106.
Fleischer, M. (1959) New mineral names. American Mineralogist: 44: 464-470.
Tennyson, C. (1961) The morphology of eskolaite, Cr2O3. American Mineralogist: 46: 998–999.
Newnham, R.E., de Haan, Y.M. (1962) Refinement of the α Al2O3, Ti2O3, V2O3 and Cr2O3 structures. Zeitschrift für Kristallographie: 117: 235-237.
Milton, C., Appleman, D.E., Appleman, M.H., Chao, E.C.T., Cuttitta, F., Dinnin, J.I., Dwornik, E.J., Ingram, B.L., Rose, H.J., Jr. (1976) Merumite, a complex assemblage of chromium minerals from Guyana. United States Geological Survey Prof. Paper 887: 1-29 + 6 plates.
Cassedanne, J., Cassedanne, J. (1980) Présence d’eskolaïte dans les alluvions stannifères de la Chapada Diamantina (Bahia-Bresil). Bulletin de Minéralogie: 103: 600–602. (French with English abs.)
Finger, L.W., Hazen, R.M. (1980) Crystal structure and isothermal compression of Fe2O3, Cr2O3, and V2O3 to 50 kbars. Journal of Applied Physics: 51: 5362-5367.
Sawada, H. (1994) Residual electron density study of chromium sesquioxide by crystal structure and scattering factor refinement. Materials Research Bulletin: 29: 239-245.
Belokoneva, E.L., Shcherbakova, Y.K. (2003) Electron density in synthetic eskolaite Cr2O3 with a corundum structure and its relation to antiferromagnetic properties. Russian Journal of Inorganic Chemistry: 48: 861-869.
Logvinova, A.M., Wirth, R., Sobolev, N.V., Seryotkin, Y.V., Yefimova, E.S., Floss, C., Taylor, L.A. (2008) Eskolaite associated with diamond from the Udachnaya kimberlite pipe, Yakutia, Russia. American Mineralogist: 93: 685-690.
Kantor, A., Kantor, I., Merlini, M., Glazyrin, K., Prescher, C., Hanfland, M., Dubrovinsky, L. (2012) High-pressure structural studies of eskolaite by means of single-crystal X-ray diffraction. American Mineralogist: 97: 1764-1770.
Alexandre, P., Peterson, R.C., Kyser, K., Layton-Matthews, D., Joy, B. (2014) High-Cr minerals from the Matoush Uranium Deposit in the Otish Basin, Quebec, Canada. The Canadian Mineralogist: 52: 61-75.

Internet Links for EskolaiteHide

Localities for EskolaiteHide

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 ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
  • Eastern Antarctica
    • Queen Maud Land
Ikeda, Y. (1992). An overview of the research consortium, "Antarctic carbonaceous chondrites with CI affinities, Yamato-86720, Yamato-82162, and Belgica-7904". Proc. NIPR Symp. Antarct. Meteorites 5: 49-73. (March 1992)
    • Transantarctic Mts
      • Buckley Island quadrangle
        • Lewis Cliff
Goodrich, C. A., & Harlow, G. E. (2001). Knorringite-uvarovite garnet and Cr-Eskola pyroxene in ureilite LEW 88774. Meteoritics and Planetary Science Supplement, 36, 68.
  • Victoria
    • City of Greater Shepparton
      • Murchison
Ma, C., Beckett, J.R., Rossman, G.R. (2010): Discovery of a new chromium sulfide mineral, Cr5S6, in Murchison. 73rd Annual Meteoritical Society Meeting, 2010
  • Bahia
    • Érico Cardoso
      • Paramirim das Crioulas
Anthony, J. W. et al. (1997): Handbook of Mineralogy, Vol. 3, 33
Jeannine and Jacques Cassedanne : "Présence d'eskolaite dans les alluvions stannifères de la Chapada Diamantina (Bahia-Brésil), Bull. Mineral., 1980, 103, pp 600-602.
    • Paramirim
[MinRec 16:111]
  • Québec
    • Nord-du-Québec
      • Baie-James
        • Otish Mts
ALEXANDRE, P., PETERSON, R.C., KYSER, K., LAYTON-MATHEWS, D. & JOY, B. (2014) High-Cr minerals from the Matoush uranium deposit in the Otish Basin, Quebec, Canada. Canadian Mineralogist 52, 61-75.; Geological Association of Canada (2014) Abstracts Fredericton Vol 37; Robichaud, L., Lafontaine, J., & White, J. C. (2011). Structural analysis of the Matoush uranium deposit, Quebec. GeoCanada 2010 – Working with the Earth
Finland (TL)
  • North Karelia
Am Min 43 (1958), 1098
Weiser, T.W., Kojonen, K.K. and Lodziak, J. (2008): New data of eskolaite, Zn-bearing chromite, willyamite and ullmannite from the Outokumpu mine, eastern Finland. Bulletin of the Geological Society of Finland, 80, 5–18. []
Geological Survey of Finland 2011. Vuonos - Copper Database
  • Schleswig-Holstein
    • Kiel
Ramdohr, P. (1973). The Opaque Minerals in Stony Meteorites. Elsevier Publishing Company: Amsterdam; London: New York. 245 pages.
  • Cuyuni-Mazaruni Region
    • Kamakusa
  • Rajasthan
    • Ajmer Division
      • Bhilwara District
Kompanchenko, A., Voloshin, A., & Balagansky, V. (2018). Vanadium mineralization in the Kola region, Fennoscandian Shield. Minerals, 8(11), 474.
  • Java
    • West Java Province
Nazarov, M. A., Brandstaetter, F. & Kurat, G. (1999) Phosphorian Sulfides from Banten and Boriskino CM Chondrites: Lunar and Planetary Science Conference XXX, abstract no. 1260. (Mar 1999)
  • Leinster
    • Co. Wicklow
      • Newton Mt. Kennedy
Oppenheim, M.J., Brück, P.M., Elsdon, R., Synge, F.M., Weaver, A. and Warren, W.P. (1977) Eskolaite, Cr2O3, from County Wicklow, Ireland. Mineralogical Magazine, vol. 41, n° 319, 402-403.; Embrey, P.G. (1978) Fourth supplementary list of British minerals. Mineralogical Magazine, vol. 42, n° 322, 169-177.
  • Okinawa
    • Senkaku Islands (Diaoyudao Islands; Diaoyutai Islands)
Ouroboros -
Fourcade et al. (2007)
  • Hardap Region
    • Gibeon
Petaev, M. I. (1997, March). Cr-bearing Minerals in the Gibeon IVA Iron: Indicators of Sulfur and Oxygen Fugacities in the Parent Body. In Lunar and Planetary Science Conference (Vol. 28, p. 1091).
  • Dhofar
Ivanova, M. A., Taylor, L. A., Clayton, R. N., Mayeda, T. K., Nazarov, M. A., Brandstaetter, F., & Kurat, G. (2002, March). Dhofar 225 vs. the CM clan: Metamorphosed or new type of carbonaceous chondrite?. In Lunar and Planetary Institute Science Conference Abstracts (Vol. 33, p. 1437).
  • Irkutsk Oblast
    • Lake Baikal area
[MinRec 27:304]; Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
      • Slyudyanka (Sludyanka)
Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow; Reznitskii, L., Clark, C. M., Hawthorne, F. C., Grice, J. D., Skogby, H., Hålenius, U., & Bosi, F. (2014). Chromo-alumino-povondraite, NaCr3 (Al4Mg2)(Si6O18)(BO3) 3 (OH) 3O, a new mineral species of the tourmaline supergroup. American Mineralogist, 99(8-9), 1767-1773.; Bosi, F., Reznitskii, L., Skogby, H., & Hålenius, U. (2014). Vanadio-oxy-chromium-dravite, NaV3 (Cr4Mg2)(Si6O18)(BO3) 3 (OH) 3O, a new mineral species of the tourmaline supergroup. American Mineralogist, 99(5-6), 1155-1162.
        • Pokhabikha River Valley
Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
  • Magadan Oblast
    • Magadan
Sharygin, V. V., Kovyazin, S. V. & Podgornykh, N. M. (2006) Mineralogy of Olivine-hosted Inclusions from the Omolon Pallasite (abstract). Lunar and Planetary Science Conference, XXXVII, abstract no.1235. (Mar 2006)
  • Republic of Karelia
    • Lake Onega
      • Zaonezhie peninsula
        • Velikaya Guba uran-vanadium deposit
Borozdin, A. P., Polekhovskii, Y. S., Bushmin, S. A., Glebovitskii, V. A., Belyatskii, B. V., & Savva, E. V. (2014, January). Age of metasomatism and ore formation in the Srednyaya Padma vanadium-precious metals-uranium deposit (Karelia, Baltic Shield). In Doklady Earth Sciences (Vol. 454, No. 1, p. 68). Springer Science & Business Media.
  • Sakha Republic (Yakutia)
    • Mirninsky District
      • Daldyn
Lawrence A. Taylor, Mahesh Anand1, Prinya Promprated1, Christine Floss and Nikolai V. Sobolev, The significance of mineral inclusions in large diamonds from Yakutia, Russia, American Mineralogist; May 2003; v. 88; no. 5-6; p. 912-920
  • Sverdlovsk Oblast
    • Asbest
Erokhin, Y. V., Khiller, V. V., Zoloev, K. K., Popov, M. P., & Grigor'ev, V. V. (2014). Mariinskite from the Bazhenovskii ophiolite complex: The second finds in the world. In Doklady Earth Sciences (Vol. 455, No. 2, p. 408). Springer Science & Business Media.
    • Karpinsk
Sharygin, V. V., & Ivanov, O. K. (2014) Cr-rich “tiooxyspinel” mineral from Kosva dunite massif, Middle Urals: possible link between spinel-and tiospinel-group minerals. 30th International Conference on “Ore Potential of Alkaline, Kimberlite and Carbonatite Magmatism”29 September – 02 October 2014 Antalya TURKEY
    • Malyshevo
      • Izumrudnye Kopi area
Pautov, L.A., Popov, M.P.,Erokhin, Y.V., Khiller, V.V. and Karpenko,V.Y. (2011): Mariinskite, IMA 2011-057. CNMNC Newsletter No. 11, December 2011, page 2888; Mineralogical Magazine, 75, 2887-2893
  • Tyumen Oblast
6th orogenic lherzolite conference 2014 Morocco; Yang, J., Meng, F., Xu, X., Robinson, P. T., Dilek, Y., Makeyev, A. B., ... & Cliff, J. (2015). Diamonds, native elements and metal alloys from chromitites of the Ray-Iz ophiolite of the Polar Urals. Gondwana Research, 27(2), 459-485.
  • California
    • San Benito Co.
      • New Idria Mining District
        • Goat Mountain
Dunning, Hadley, Cooper, Magnasco collections
  • Kentucky
    • Calloway Co.
Palmer, E.E. & Lauretta, D.S. (Oct 2011) Aqueous alteration of kamacite in CM chondrites: Meteoritics & Planetary Science: 46 (10): 1587-1607 (Oct 2011)
  • Utah
    • San Juan Co.
Schulze, D. J., Flemming, R. L., Shepherd, P. H., & Helmstaedt, H. (2014). Mantle-derived guyanaite in a Cr-omphacitite xenolith from Moses Rock diatreme, Utah. American Mineralogist, 99(7), 1277-1283.
The Moon
  • Mare Crisium
Mokhov, A.V., Kartashov, P.M., Bogatikov, O.A. (2007) Moon under a microscope, - Moscow, Nauka, p. 128 (in Russian).
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