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Marie Skłodowska Curie
Mg(UO2)2(SiO3OH)2 · 6H2O
Light yellow to ...
Adamantine, Vitreous, Silky
2 - 3
Named after Marie Sklodowska-Curie (1867-1934) who, with her husband Pierre, was a pioneer in the study of radioactivity.

Classification of Sklodowskite

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

9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates

53 : NESOSILICATES Insular SiO4 Groups and Other Anions or Complex Cations
3 : Insular SiO4 Groups and Other Anions of Complex Cations with (UO2)

14 : Silicates not Containing Aluminum
16 : Silicates of U

Physical Properties of Sklodowskite

Adamantine, Vitreous, Silky
Diaphaneity (Transparency):
Transparent, Translucent
earthy when massive
Light yellow to green-yellow
Hardness (Mohs):
2 - 3
on {100}
3.54 g/cm3 (Measured)    3.51 g/cm3 (Calculated)

Optical Data of Sklodowskite

Biaxial (+)
RI values:
nα = 1.613 - 1.615 nβ = 1.635 - 1.642 nγ = 1.656 - 1.657
Max Birefringence:
δ = 0.043
Image shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:
strong r > v
X= colorless
Y= yellow
Z= pale yellow

Chemical Properties of Sklodowskite

Mg(UO2)2(SiO3OH)2 · 6H2O
Elements listed in formula:
Common Impurities:

Crystallography of Sklodowskite

Crystal System:
Class (H-M):
2/m - Prismatic
Space Group:
Space Group Setting:
Cell Parameters:
a = 17.382(6) Å, b = 7.047(1) Å, c = 6.610(2) Å
β = 105.88°
a:b:c = 2.467 : 1 : 0.938
Unit Cell Volume:
V 778.77 ų (Calculated from Unit Cell)
Acicular crystals
With {001} or {100} as twin plane

Occurrences of Sklodowskite

Type Occurrence of Sklodowskite

Relationship of Sklodowskite to other Species

Other Members of Group:
CuprosklodowskiteCu(UO2)2(SiO3OH]2 · 6H2O
OursiniteCo(UO2)2(SiO3OH)2 · 6H2O
9.AK.05Soddyite(UO2)2SiO4 · 2H2O
9.AK.10CuprosklodowskiteCu(UO2)2(SiO3OH)2 · 6H2O
9.AK.10OursiniteCo(UO2)2(SiO3OH)2 · 6H2O
9.AK.15Boltwoodite(K,Na)UO2(SiO3OH) · 1.5H2O
9.AK.15KasolitePb(UO2)SiO4 · H2O
9.AK.15NatroboltwooditeNa(UO2)(SiO3OH) · H2O
9.AK.15Uranophane-βCa(UO2)2(SiO3OH)2 · 5H2O
9.AK.15UranophaneCa(UO2)2(SiO3OH)2 · 5H2O
9.AK.15Beta-UranophaneCa(UO2)2(SiO3OH)2 · 5H2O
9.AK.20Swamboite-(Nd)U6+(UO2)6(SiO3OH)6 · 30H2O
9.AK.25HaiweeiteCa(UO2)2Si5O12(OH)2 · 6H2O
9.AK.25MetahaiweeiteCa(UO2)2Si6O15 · nH2O
9.AK.25RanquiliteCa(UO2)2[Si5O12(OH)2] · 6H2O
9.AK.30WeeksiteK2(UO2)2(Si5O13) · 4H2O
9.AK.30CoutinhoiteThxBa1-2x(UO2)2Si5O13 · 3H2O
9.AK.35UrsiliteMg4(UO2)4(Si2O5)5.5(OH)5 · 13H2O
9.AK.35MagnioursiliteMg4(UO2)4(Si2O5)5(OH)6 · 20H2O
9.AK.35CalcioursiliteCa4(UO2)4(Si2O5)5(OH)6 · 15H2O
14.16.3Soddyite(UO2)2SiO4 · 2H2O
14.16.4Swamboite-(Nd)U6+(UO2)6(SiO3OH)6 · 30H2O
14.16.5WeeksiteK2(UO2)2(Si5O13) · 4H2O
14.16.6Boltwoodite(K,Na)UO2(SiO3OH) · 1.5H2O
14.16.7NatroboltwooditeNa(UO2)(SiO3OH) · H2O
14.16.8CuprosklodowskiteCu(UO2)2(SiO3OH)2 · 6H2O
14.16.10UranophaneCa(UO2)2(SiO3OH)2 · 5H2O
14.16.11Uranophane-βCa(UO2)2(SiO3OH)2 · 5H2O
14.16.12HaiweeiteCa(UO2)2Si5O12(OH)2 · 6H2O
14.16.13MetahaiweeiteCa(UO2)2Si6O15 · nH2O
14.16.17KasolitePb(UO2)SiO4 · H2O
14.16.18OrlitePb3(UO2)3(Si2O7)2 · 6H2O
14.16.19OursiniteCo(UO2)2(SiO3OH)2 · 6H2O

Other Names for Sklodowskite

Name in Other Languages:
Simplified Chinese:硅镁铀矿
Traditional Chinese:矽鎂鈾礦

Other Information

Health Risks:

References for Sklodowskite

Reference List:
Schoep, A. (1924) La Sklodowskite, nouveau minéral radioactif. Comptes rendu de l’Académie des sciences de Paris: 179: 413.

Foshag, W.F. (1925) New mineral names. American Mineralogist: 10: 132.

Gorman, D.H. (1957) Studies of radioactive compounds; IX, Sklodowskite. Canadian Mineralogist: 6: 52-60.

Mokeeva, V.I. (1964) The structure of sklodowskite. Soviet Physics - Crystallography: 9: 217-218.

Ryan, R.R., Rosenzweig, A. (1977) Sklodowskite, MgO.2UO3.2SiO2.7H2O. Crystal Structure Communications: 6: 611-615.

Stohl, F.V., Smith, D.K. (1981) The crystal chemistry of the uranyl silicate minerals. American Mineralogist: 66: 615-625.

Burns, P.C. (2005) U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures. Canadian Mineralogist: 43: 1839-1894.

Internet Links for Sklodowskite URL:
Please feel free to link to this page.
The following Sklodowskite specimens are currently listed for sale on

Localities for Sklodowskite

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.
(TL) indicates type locality for a valid mineral species. (FRL) indicates first recorded locality for everything else. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
  • Northern Territory
    • Coomalie Shire
      • Batchelor
        • Rum Jungle
D A Berkman (1968) The geology of the Rum Jungle Uranium Deposits. Symposium on Uranium Deposits in Australia 1968 pp.12-31; Geosciences, Museums Victoria
    • West Arnhem Region
      • Kakadu
Economic Geology of Australia and papua New Guinea pp321-326
Angela Giblin (2004) Alligator Rivers Uranium deposits (Koongarra, Nabarlek and Ranger One) Northern Territory. CRC LEME; Isobe, H., Murakami, T., & Ewing, R. C. (1992). Alteration of uranium minerals in the Koongarra deposit, Australia: Unweathered zone. Journal of Nuclear Materials, 190, 174-187.
Econ Geol (1987)82:1152-1168; Angela Giblin (2004) Alligator Rivers Uranium deposits (Koongarra, Nabarlek and Ranger One) Northern Territory. CRC LEME
  • Bahia
    • Brumado (Bom Jesus dos Meiras)
      • Serra das Éguas
Cassedanne, J.P. & Cassedanne, J.O. (1978): Famous mineral localities: The Brumado district, Bahia , Brazil. Mineralogical Record 9 : 196-205
    • Lagoa Real U province
A.M.D.V. Chaves (2005) Mineralogia e Geoquímica Supergênicas do Urânio - Província Uranífera de Lagoa Real, Caetité-Bahia. Dissertação de Mestrado, Comissão Nacional de Energia Nuclear, 101p. (In portuguese with abstract in english)
  • Saskatchewan
    • Athabasca Basin
WATKINSON, D.H., HESLOP, J.B. & EWERT, W.D. (1975) Nickel sulphide-arsenide assemblages associated with uranium mineralization, Zimmer Lake area, Northern Saskatchewan. Canadian Mineralogist 13, 198-204.
Shuling Zhang, Gong Chen, and Yuheng Tang (1984): Acta Sedimentologica Sinica 2(4)
Czech Republic
  • Bohemia (Böhmen; Boehmen)
    • Central Bohemia Region
Pauliš P., Kopecký S., Černý P. 2007: Uranové minerály České Republiky a jejich naleziště. 1. část. (Kutna Hora, issue 1)
    • Karlovy Vary Region
      • Krušné Hory Mts (Erzgebirge)
        • Jáchymov District (St Joachimsthal)
Lapis 2002(7/8), 63-65
            • Svornost Mine (Einigkeit Mine)
Jiří Sejkora, Jakub Plášil & Bohuslav Bureš (2013): Neobvyklá asociaci supergenních minerálů uranu ze žíly Jan Evangelista, Jáchymov (Česká republika). [Unusual association of supergene uranium minerals from the Jan Evangelista vein, Jáchymov (Czech Republic)]. Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha) 21, 143-156
    • Liberec Region
      • Harrachov (Harrachsdorf)
Bradna, J., Šita, F.: Nálezy minerál na Rýžovišti u Harrachova. Opera Corcontica, 1968, 5, s. 246-247.
Democratic Republic of Congo (Zaïre)
  • Katanga (Shaba)
    • Katanga Copper Crescent
      • Kolwezi District
        • Kamoto
S. Wolfsried collection
        • Kolwezi
No reference listed
      • Lubumbashi (Elizabethville)
      • Shinkolobwe
Am Min 66 (1981), 610
      • Swambo
  • Brittany
    • Morbihan
      • Berné
R. Pierrot, L. Chauris, C. Laforêt and F. Pillard : "Inventaire Minéralogique de la France N° 9 : Morbihan", BRGM, 1980.
      • Guern
Le Règne Minéral, Hors Série IV (1998)
  • Occitanie
    • Hérault
      • Lodève
[Le Règne Minéral 1997, 13, p.5-18]; Bariand, P., Bachet, B., Brassy, C., Medenbach, O., Deliens, M., Vautier, R., & Piret, P. (1993) A New Uranium Mineral from the Talmessi Mine, Iran, and Rabejac, France. Mineralogical Record: 24: 463-467
Le Règne Minéral, Hors Série IV (1998)
  • Baden-Württemberg
    • Black Forest
      • Menzenschwand
Walenta: "Die Mineralien des Schwarzwaldes", Weise (Munich), 1992
      • Wolfach
        • Oberwolfach
          • Rankach valley
Uwe Kolitsch (to be published;,40632.msg303314.html#msg303314)
  • Bavaria
    • Franconia
      • Fichtelgebirge
        • Weißenstadt
          • Großschloppen
Gunnar Farber
    • Upper Palatinate
      • Wölsendorf Fluorite Mining District
        • Wölsendorf East District
          • Schwarzach bei Nabburg
            • Wölsendorf
Weiss: "Mineralfundstellen, Deutschland West", Weise (Munich), 1990
  • Rhineland-Palatinate
    • Hunsrück
      • Birkenfeld
        • Ellweiler
Aufschluss 69/(7+8), Lapis 79/(7+8)
  • Saxony
    • Vogtland
      • Oelsnitz
Gröbner, J. and Kolitsch, U. (2007): The minerals of the uranium prospect at Tirpersdorf, Vogtland. Lapis 32, 37-42; 58. (in German)
  • Thuringia
    • Gera
      • Ronneburg U deposit
T. Witzke & F. Rüger: Lapis 1998(7/8), 26-64
  • Attikí Prefecture (Attica; Attika)
    • Lavrion District (Laurion; Laurium)
      • Lavrion District Mines
        • Paleokamariza area
          • Paleokamariza Mines
Analysed by Michalis Fitros - personal communication
  • Honshu Island
    • Tohoku Region
      • Fukushima Prefecture
Matsubara, S., Miyawaki, R., Yokoyama, K., Momma, K., Shigeoka, M., & Hashimoto, E. (2013) Pyrochlore and microlite in a pegmatite at Atagoyama, Koriyama City, Fukushima Prefecture, Japan. Bull. Natl. Mus. Nat. Sci., Ser. C, 39, pp. 1–6
  • Chihuahua
    • Mun. de Aquiles Serdán
      • Santa Eulalia District
        • West Camp
          • Francisco Portillo
Panczner(1987):220 & 284.
New Zealand
  • South Island
    • Buller River
Christie & Brathwaite, (2000) NZ Mineral Commodity Report 19 - Beryllium, Gallium, Lithium, Magnesium, Uranium and Zirconium
  • Lower Silesia (Dolnośląskie)
    • Jelenia Góra District
      • Kowary area
Mochnacka, K., Banaś, M. (2000): Occurrence and genetic relationships of uranium and thorium mineralization in the Karkonosze-Izera Block (The Sudety Mts, SW Poland). Annales Societatis Geologorum Poloniae: 70: 137-150
  • Suceava Co.
    • Suceava district
Hîrtopanu P., Udubaşa G., Scott P., Hârtopanu I. (2004) Uranium sulphide mineralisation in the Bistriţa Mts., East Carpathians, Romania. Romanian Journal of Mineral Deposits 81:108-111
  • Wallis (Valais)
    • Le Trient Valley
      • Les Marécottes
Stalder, H. A., Wagner, A., Graeser, S. and Stuker, P. (1998): "Mineralienlexikon der Schweiz", Wepf (Basel), p. 374.
  • Viloyati Sogd (Viloyati Sughd; Viloyati Khodzhent; Viloyati Leninabad)
    • Khodzhent (Leninabad)
      • Kyzyltyube-Sai
Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
  • Alaska
    • Prince of Wales-Outer Ketchikan Borough
      • Ketchikan District
        • Prince of Wales Island
          • Bokan Mountain
U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
  • California
    • San Bernardino Co.
      • Bristol Mts
        • Amboy area
W. Wise - X-ray work at U.C. Santa Barbara
  • Colorado
    • Saguache Co.
      • Marshall Pass District
Minerals of Colorado (1997) E.B. Eckels
  • Michigan
    • Gogebic Co.
      • Watersmeet
Travis Olds collection
  • New Hampshire
    • Grafton Co.
      • Grafton
Frondel, C., 1956, Mineral Composition of Gummite, American Mineralogist, v. 41, p. 539-568.
  • New Mexico
    • Cibola Co.
Northrop, Minerals of New Mexico, 3rd. rev. ed. (1996)
NMBMMR Memoir 15 Geology and Technology of the Grants Uranium Region
    • McKinley Co.
Northrop, Minerals of New Mexico, 3rd Rev. Ed., 1996
    • Sierra Co.
RRUFF R050445
    • Socorro Co.
      • San Lorenzo District
Patrick Haynes
  • New York
    • Essex Co.
      • Crown Point Township
Jensen (1978) Minerals of New York State
George Robinson & Steven Chamberlain (2007) Gazetteer of major New York State mineral localities. Rocks & Minerals, 82, #6, 472-483.
  • Pennsylvania
    • Carbon Co.
      • Jim Thorpe (Mauch Chunk)
Geyer, A.R., Smith, R.C. & Barnes, J.H. (1976) Mineral Collecting in Pennsylvania.
  • Utah
    • Juab Co.
UGMS Bull 117 Minerals and Mineral Localities of Utah; USGS Prof Paper 455 p57
Rocks & Minerals: 68(6): 381-393.
    • Piute Co.
      • Marysvale District (Marysvale Uranium area)
UGMS Bull 117 Minerals and Mineral Localities of Utah
    • San Juan Co.
      • White Canyon District
        • White Canyon
Can Min (2001) 39, 6, 1685-1689
    • Wayne Co.
      • Fremont District
        • Fruita
UGMS Bull 117 Minerals and Mineral Localities of Utah
  • Washington
    • Stevens Co.
      • Spokane Indian Reservation
        • Turtle Lake
Cannon, B. (1975): Minerals of Washington, p.53; George E. Becraft and Paul L. Weis (1963) Geology and mineral deposits of the Turtle Lake quadrangle, Washington. USGS Bulletin 1131
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