Carnotite


Carnotite

Infobox mineral
name = Carnotite
category =
boxwidth =
boxbgcolor =


imagesize = 200
caption =
formula = K2(UO2)2 (VO4)2·3H2O
molweight =
color = Yellow, Golden yellow, Greenish yellow
habit = crusts, earthy masses, foliated and granular aggregates.
system = Monoclinic; 2/m
twinning =
cleavage = perfect: one direction
fracture = uneven
mohs = 2
luster = pearly to dull or earthy
refractive = nα=1.750 - 1.780,
nβ=1.901 - 2.060,
nγ=1.920 - 2.080
opticalprop =
birefringence =
pleochroism =
streak = yellow
gravity = 4 - 5
density =
melt =
fusibility =
diagnostic =
solubility =
diaphaneity =
other = ,
not fluorescent

Carnotite is a potassium uranium vanadate mineral with chemical formula: K2(UO2)2(VO4)2·3H2O. The water content can vary and small amounts of calcium, barium, magnesium, iron, and sodium are often present.

Carnotite is a bright to greenish yellow mineral that occurs typically as crusts and flakes in sandstones. Amounts as low as one percent will color the sandstone a bright yellow. The high uranium content makes carnotite an important uranium ore and also radioactive. It is a secondary vanadium and uranium mineral usually found in sedimentary rocks in arid climates. It is an important ore of uranium in the Colorado Plateau region of the United States where it occurs as disseminations in sandstone and concentrations around petrified logs. Occurs in the states of Wyoming; Colorado; Arizona; Utah; It also occurs incidentally in Grants, New Mexico and Carbon County, Pennsylvania. It is also reported in Zaire; Morocco; Radium Hill, Australia; and Kazakhstan.

The mineral was first described in 1899 by French scientists M. M. C. Freidel and E. Cumenge, who identified it in specimens from Roc Creek in Montrose County, Colorado, United States. [Robert J. Wright and Donald L. Everhart (1960) "Uranium", in "Mineral Resources of Colorado First Sequel", State of Colorado Mineral Resources Board, p.330-331.] It is named for Marie Adolphe Carnot (1839 - 1920), French mining engineer and chemist.

Several related mineral species exist, including: margaritasite ((Cs,K,H3O)2(UO2)(VO4)2·H2O) and tyuyamunite, (Ca(UO2)2(VO4)2·5-8H2O).

ee also

*List of minerals
*List of minerals named after people

References

*Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., John Wiley and Sons, New York ISBN 0-471-80580-7
* [http://webmineral.com/data/Carnotite.shtml Webmineral]
* [http://www.evsc.virginia.edu/tours/rockmin/carnotite.shtml Univ. of Virginia]
* [http://mineral.galleries.com/minerals/phosphat/carnotit/carnotit.htm Mineral Galleries]
* [http://www.mindat.org/min-907.html Mindat.org]


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Look at other dictionaries:

  • Carnotite — Catégorie VIII : phosphates, arséniates, vanadates[1] Carnotite du Colorado (États Unis) …   Wikipédia en Français

  • CARNOTITE — Vanadate hydraté d’uranium et de potassium de formule chimique: K2(UO2)2(VO4)23H2O, qui doit son nom de carnotite au savant français Marie Adolphe Carnot (1839 1920). À l’analyse chimique, elle apparaît composée de 10,4 p. 100 de K2O, de 63,4 p.… …   Encyclopédie Universelle

  • carnotite — [kär′nə tīt΄] n. [after A. Carnot (died 1920), Fr mine inspector + ITE1] a yellow, very soft, radioactive, monoclinic mineral, K2 (UO2) 2 (VO4) 2·3H2O, that is a source of uranium, radium, and vanadium …   English World dictionary

  • carnotite — /kahr neuh tuyt /, n. Mineral. a yellow, earthy, hydrous potassium uranium vanadate: an ore of uranium. [1895 1900; named after A. Carnot (d. 1920), French mining official; see ITE1] * * * ▪ mineral  radioactive, bright yellow, soft and earthy… …   Universalium

  • carnotite — karnotitas statusas T sritis chemija apibrėžtis Mineralas. formulė K₂[(UO₂)₂|V₂O₈]·3H₂O atitikmenys: angl. carnotite rus. карнотит …   Chemijos terminų aiškinamasis žodynas

  • carnotite — noun Etymology: French, from M. A. Carnot died 1920 French inspector general of mines Date: 1899 a yellow to greenish yellow mineral consisting of a radioactive hydrous vanadate of uranium and potassium that is a source of radium and uranium …   New Collegiate Dictionary

  • carnotite — noun A yellow mineral that is a potassium uranyl vanadate that is a major ore or uranium, with the chemical formula K(UO)(VO)·3HO …   Wiktionary

  • carnotite — car·no·tì·te s.f. TS mineral. minerale di colore giallo, costituito da vanadato idrato di potassio e uranile, utilizzato per l alto contenuto di uranio {{line}} {{/line}} DATA: 1931. ETIMO: der. di Carnot, nome del chimico e mineralogista… …   Dizionario italiano

  • carnotite — {{hw}}{{carnotite}}{{/hw}}s. f. Minerale di color giallo, da cui si ricava uranio …   Enciclopedia di italiano

  • carnotite — pl.f. carnotiti …   Dizionario dei sinonimi e contrari


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