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Uraninite

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Formula:
UO2
Colour:
Black, brownish-black, greyish, greenish; green-gray (thin fragments)
Lustre:
Greasy, Sub-Metallic, Dull
Hardness:
5 - 6
Specific Gravity:
10.63 - 10.95
Crystal System:
Isometric
Member of:
Name:
Renamed in 1845 by Wilhelm Karl von Haidinger for its composition containing uranium. Originally recognized before the element uranium was known and called "schwarz beck-erz" by Franz Ernst Brückmann in 1727. Subsequently described with several names including "pseudogalena" and "pitch-like zinc-blende" by Johan Gottschalk Wallerius (Vallerius) in 1747. Named pechblende by Axel Cronstedt in 1758. Named "uranerz" by Martin Klaproth after he discovered the element uranium in this mineral. Many spelling variations of the above-mentioned names are known.
Uraninite Group. Thorianite-Uraninite Series.

Occurs in granitic and syenitic pegmatites. Colloform crusts in high-temperature hydrothermal veins. In quartz-pebble conglomerates.

Typical uranium ore contains ca. 0.1 mg of Po / metric ton; Ra is more abundant, by 0.14 g of Ra / metric ton; 231Pa is present in a very tiny amount, usually as low as 0.1 ppm, but may reach 3 ppm; traces of Np (isotopes with masses from 237 to 240) and 238Pu are also detectable. Kenna & Kuroda (1964) report values as low as 2.5–3.1 × 10−10 g for technetium (99Tc) per kg of African material. Traces of Cm are possible but have not yet been detected.

Compare 'UM1978-10-O:U'.


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Classification of UraniniteHide

Approved, 'Grandfathered' (first described prior to 1959)
4.DL.05

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
L : With large (+- medium-sized) cations; fluorite-type structures
5.1.1.1

5 : OXIDES CONTAINING URANIUM OR THORIUM
1 : AXO2·xH2O
7.16.1

7 : Oxides and Hydroxides
16 : Oxides of U

Pronounciation of UraniniteHide

Pronounciation:
PlayRecorded byCountry
Jolyon & Katya RalphUnited Kingdom

Physical Properties of UraniniteHide

Greasy, Sub-Metallic, Dull
Transparency:
Opaque
Colour:
Black, brownish-black, greyish, greenish; green-gray (thin fragments)
Streak:
Brownish black, grayish, olive-green
Hardness:
5 - 6 on Mohs scale
Hardness:
VHN50=499 - 548 kg/mm2 - Vickers
Tenacity:
Brittle
Fracture:
Irregular/Uneven, Conchoidal
Density:
10.63 - 10.95 g/cm3 (Measured)    10.88 g/cm3 (Calculated)
Comment:
Decreasing with oxidation to low as 6.5

Optical Data of UraniniteHide

Type:
Isotropic
Type:
Isotropic
Colour in reflected light:
Light grey with brownish tint
Internal Reflections:
Dark brown

Chemical Properties of UraniniteHide

Formula:
UO2
CAS Registry number:
1344-57-6

CAS Registry numbers are published by the American Chemical Society
Common Impurities:
Th,Zr,Pb,Ra,Ac,Po,Ce,Y,Er,La

Age informationHide

Age range:
Paleoproterozoic to Neogene : 1737 ± 20 Ma to 21 ± 0.4 Ma - based on mindat.org data.

Crystallography of UraniniteHide

Crystal System:
Isometric
Class (H-M):
m3m (4/m 3 2/m) - Hexoctahedral
Space Group:
Fm3m
Cell Parameters:
a = 5.4682 Å
Unit Cell V:
163.51 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Octahedral, cubooctahedral, and cubic crystals; dodecahedrons less common. Massive, botryoidal, reniform, banded, columnar, curved lamellar.
Twinning:
On {111}, rare.
Comment:
Synthetic material UO2.03

Type Occurrence of UraniniteHide

Synonyms of UraniniteHide

Other Language Names for UraniniteHide

Varieties of UraniniteHide

ArsenuranArsenoan uraninite
CleveiteA REE-and Th-bearing variety of uraninite. Presence of (Y, Ce, etc.)2O3 extends to at least 10%. Related to bröggerite.
The first portions of terrestrial Helium (He) were obtained during Cleveite dissolution in sulfuric acid (Ramsey 23 March of 1895 - 2...
NiveniteA REE-bearing variety of uraninite. Presence of (Y,Ce,etc.)2O3 extends to at least 10%.
PitchblendeA massive, often globular, possibly impure, variety of Uraninite.
Sooty UraniniteFine disperse mixture of uranium minerals of black colour, mainly composed by Uraninite or more rare Ningyoite. Usual form of redeposition of U from solutions in reduced conditions of cementation zones.
Thorian UraniniteTh-bearing variety of uraninite from Ånnerud (Ånnerød), Moss, Østfold, Norway.
Uranoniobite (of Hermann)A crystalline variety previously thought to contain Nb

Relationship of Uraninite to other SpeciesHide

Member of:
Other Members of this group:
Cerianite-(Ce)(Ce4+,Th)O2Iso. m3m (4/m 3 2/m) : Fm3m
ThorianiteThO2Iso. m3m (4/m 3 2/m)
Forms a series with:

Common AssociatesHide

Associated Minerals Based on Photo Data:
Uranophane102 photos of Uraninite associated with Uranophane on mindat.org.
Gummite81 photos of Uraninite associated with Gummite on mindat.org.
Autunite43 photos of Uraninite associated with Autunite on mindat.org.
Zircon37 photos of Uraninite associated with Zircon on mindat.org.
Calcite33 photos of Uraninite associated with Calcite on mindat.org.
Fluorite31 photos of Uraninite associated with Fluorite on mindat.org.
Meta-autunite29 photos of Uraninite associated with Meta-autunite on mindat.org.
Quartz25 photos of Uraninite associated with Quartz on mindat.org.
Curite24 photos of Uraninite associated with Curite on mindat.org.
Muscovite22 photos of Uraninite associated with Muscovite on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

4.DL.05Cerianite-(Ce)(Ce4+,Th)O2Iso. m3m (4/m 3 2/m) : Fm3m
4.DL.05ThorianiteThO2Iso. m3m (4/m 3 2/m)
4.DL.05Zirkelite(Ti,Ca,Zr)O2-xIso.
4.DL.05Aeschynite Group
4.DL.10CalzirtiteCaZr3TiO9Tet.
4.DL.10Tazheranite(Zr,Ti,Ca)O2-xIso.
4.DL.10Hiärneite(Ca,Mn,Na)2(Zr,Mn3+)5(Sb,Ti,Fe)2O16Tet. 4/mmm (4/m 2/m 2/m) : I41/acd

Related Minerals - Dana Grouping (8th Ed.)Hide

5.1.1.2ThorianiteThO2Iso. m3m (4/m 3 2/m)

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

7.16.2Schoepite(UO2)8O2(OH)12 · 12H2OOrth. mmm (2/m 2/m 2/m) : Pbca
7.16.3ParaschoepiteUO3 · 2H2OOrth.
7.16.4MetaschoepiteUO3 · 1-2H2OOrth. mmm (2/m 2/m 2/m) : Pbcn
7.16.5MetastudtiteUO4 · 2H2OOrth. mmm (2/m 2/m 2/m) : Pnma
7.16.6Studtite[(UO2)(O2)(H2O)2] · H2OMon.
7.16.7IanthiniteU4+(UO2)5O7 · 10H2OOrth. mm2 : Amm2
7.16.8CompreignaciteK2(UO2)6O4(OH)6 · 7H2OOrth.
7.16.9VandenbrandeiteCu(UO2)(OH)4Tric. 1 : P1
7.16.10RoubaultiteCu2(UO2)3(CO3)2O2(OH)2•4H2OTric. 1 : P1
7.16.11BecquereliteCa(UO2)6O4(OH)6 · 8H2OOrth. mm2 : Pna21
7.16.12RameauiteK2Ca(H[3]2O)(H[5]2O)4[(UO2)6O6(OH)4](H[4]2O)Mon. m : Bb
7.16.13AgrinieriteK2(Ca,Sr)[(UO2)3O3(OH)2]2 · 5H2OOrth.
7.16.14ProtasiteBa(UO2)3O3(OH)2 · 3H2OMon.
7.16.15BillietiteBa(UO2)6O4(OH)6 · 4-8H2OOrth. mm2
7.16.16BauranoiteBa(UO2)2(OH)6 · 1-2H2O
7.16.17Metacalciouranoite(Ca,Ba,Pb,K2)U2O7 · 2H2O
7.16.18Calciouranoite(Ca,Ba,Pb)U2O7 · 5H2O
7.16.19OrthobranneriteU4+U6+Ti4O12(OH)2Orth.
7.16.20Thorutite(Th,U,Ca)Ti2(O,OH)6Mon.
7.16.21Davidite-(La)(La,Ce)(Y,U,Fe)(Ti,Fe)20(O,OH)38Trig.
7.16.22Davidite-(Ce)(Ce,La)(Y,U,Fe)(Ti,Fe)20(O,OH)38Trig. 3 : R3
7.16.23Brannerite(U4+,REE,Th,Ca)(Ti,Fe3+,Nb)2(O,OH)6Mon. 2/m : B2/m
7.16.24FourmarieritePb(UO2)4O3(OH)4 · 4H2OOrth.
7.16.25Richetite(Fe3+,Mg)Pb 8.6(UO2)36O36(OH)24•41H2O Tric.
7.16.26CuritePb3(UO2)8O8(OH)6 · 3H2OOrth. mmm (2/m 2/m 2/m) : Pnma
7.16.27MasuyitePb(UO2)3O3(OH)2 · 3H2OOrth.
7.16.28VandendriesscheitePbU7O22 · 12H2O
7.16.29MetavandendriesscheitePbU7O22 · nH2O n < 12Orth.
7.16.30SayritePb2(UO2)5O6(OH)2 · 4H2OMon.
7.16.31Wölsendorfite(Pb,Ca)U2O7 · 2H2OOrth. mmm (2/m 2/m 2/m) : Cmcm
7.16.32Clarkeite(Na,Ca,Pb)(UO2)O(OH) · 0-1H2OTrig.
7.16.33UranosphaeriteBi(UO2)O2(OH)Mon. 2/m

Fluorescence of UraniniteHide

Other InformationHide

Health Risks:
Contains uranium - always wash hands after handling. Avoid inhaling dust when handling or breaking. Never lick or ingest. Avoid prolonged exposure in the proximity of the body. Store away from inhabited areas.

References for UraniniteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Klaproth, M.H. (1797) Chemische Untersuchung des Uranerzes, Beiträge zur chemischen Kenntniss der Mineralkörper, Zweiter Band, Rottmann Berlin, 197-221.
Hillebrand (1893) USGS Bulletin 113: 37.
Goldschmidt, Thomassen (1923) Vidensk. Selsk. Skr. Mat.-nat. Kl.: 2.
Aubel (1927) C.R.: 185: 586.
Parsons (1932) Univ. Toronto Stud., Geol. Ser.: 32: 17.
Ellsworth (1935) American Journal of Science: 9: 127.
Shaub, B.M. (1938) The occurrence, crystal habit and composition of the uraninite from the Ruggles Mine, near Grafton Center, New Hampshire. American Mineralogist: 23: 334-341.
Palache, C., Berman, H., Frondel, C. (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: 611-620.
Rundle, R.E., Baenziger, N.C., Wilson, A.S., McDonald, R.A. (1948) The Structures of the Carbides, Nitrides and Oxides of Uranium. Journal of the American Chemical Society: 70: 99-105.
(1958) US Geological Survey Bulletin 1064: 11-47.
Kenna, B.T., Kuroda, P.K. (1964) Technetium in nature. Journal of Inorganic and Nuclear Chemistry: 26(4): 493-499.
Haji-Vassiliou, A. (1974) Uranium mineralization - Uraninite. Mineralogical Record: 5: 79.
Snetsinger, K.G., Polkowski, G. (1977) Rare accessory uraninite in a Sierran granite. American Mineralogist: 62: 587-589.
Finch, R.J., Ewing, R.C. (1992) The corrosion of uraninite under oxidizing conditions. Journal of Nuclear Materials: 190: 133-156.
Pearcy, E.C., Prikryl, J.D., Murphy, W.M., Leslie, B.W. (1994) Alteration of uraninite from the Nopal I deposit, Peña Blanca District, Chihuahua, Mexico, compared to degradation of spent nuclear fuel in the proposed U.S. high-level nuclear waste repository at Yucca Mountain, Nevada. Applied Geochemistry: 9: 713-732.
Greenwood, N.N., Earnshaw, A. (1997) Chemistry of the Elements. Butterworth–Heinemann.
Abdelouas, A., Lutze, W., Nuttall, H.E. (1999) Oxidative dissolution of uraninite precipitated on Navajo sandstone. Journal of Contaminant Hydrology: 36: 353-375.
Alexandre, P., Kyser, T.K. (2005) Effects of cationic substitutions and alteration in uraninite, and implications for the dating of uranium deposits. The Canadian Mineralogist: 43: 1005-1017.
Fayek, M., Utsunomiya, S., Pfiffner, S.M., White, D.C., Riciputi, L.R., Ewing, R.C., Anovitz, L.M., Stadermann, F.J. (2005) The application of HRTEM techniques and nanosims to chemically and isotopically characterize Geobacter Sulfurreducens surfaces. The Canadian Mineralogist: 43: 1631-1641. [bioprecipitation of uraninite].
Plášil, J. (2014) Oxidation–hydration weathering of uraninite: the current state-of-knowledge. Journal of Geosciences: 59: 99-114.
Alexandre, P., Peterson, R., Joy, B. (2015) Sector zoning in uraninite. The Canadian Mineralogist: 53 (4) p. 693-703.
http://periodic.lanl.gov/88.shtml (Los Alamos National Laboratory) (2016).
http://periodic.lanl.gov/91.shtml (Los Alamos National Laboratory) (2016).
http://periodic.lanl.gov/93.shtml (Los Alamos National Laboratory) (2016).
http://periodic.lanl.gov/94.shtml (Los Alamos National Laboratory) (2016).
http://periodic.lanl.gov/96.shtml (Los Alamos National Laboratory) (2016).

Internet Links for UraniniteHide

Localities for UraniniteHide

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