Difference between revisions of "Uraninite" - New World Encyclopedia
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{{Infobox mineral | {{Infobox mineral | ||
| name = Uraninite | | name = Uraninite | ||
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| pleochroism = None | | pleochroism = None | ||
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| gravity = 7.5 - 10 | | gravity = 7.5 - 10 | ||
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| − | '''Uraninite''' is a [[uranium]]-rich [[mineral]] with a composition that is largely UO<sub>2</sub> ([[uranium dioxide]]), but which also contains [[uranium trioxide|UO<sub>3</sub>]] and [[oxide]]s of [[lead]], [[thorium]], and [[Rare earth element|rare earth]]s. It is most commonly known in the variety '''pitchblende''' (from ''pitch'', because of its black color, and ''blende'', a term used by [[ | + | '''Uraninite''' is a [[uranium]]-rich [[mineral]] with a composition that is largely UO<sub>2</sub> ([[uranium dioxide]]), but which also contains [[uranium trioxide|UO<sub>3</sub>]] and [[oxide]]s of [[lead]], [[thorium]], and [[Rare earth element|rare earth]]s. It is most commonly known in the variety '''pitchblende''' (from ''pitch'', because of its black color, and ''blende'', a term used by [[Germany|German]] miners to denote minerals whose weight suggested metal content, but whose exploitation was, at the time they were named, either impossible or not economically feasible). |
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| + | == Occurrence == | ||
Uraninite is a major ore of uranium. An important occurrence of pitchblende is at [[Great Bear Lake]] in the [[Northwest Territories]] of [[Canada]], where it is found in large quantities associated with [[silver]]. Some of the highest grade uranium occurrences in the world occur in the [[Athabasca Basin]] in northern [[Saskatchewan]]. It also occurs in [[Australia]], [[Germany]], [[England]], and [[South Africa]], and in [[New Hampshire]], [[Connecticut]], [[North Carolina]], [[Wyoming]], [[Colorado]] and [[New Mexico]] in the [[United States]]. | Uraninite is a major ore of uranium. An important occurrence of pitchblende is at [[Great Bear Lake]] in the [[Northwest Territories]] of [[Canada]], where it is found in large quantities associated with [[silver]]. Some of the highest grade uranium occurrences in the world occur in the [[Athabasca Basin]] in northern [[Saskatchewan]]. It also occurs in [[Australia]], [[Germany]], [[England]], and [[South Africa]], and in [[New Hampshire]], [[Connecticut]], [[North Carolina]], [[Wyoming]], [[Colorado]] and [[New Mexico]] in the [[United States]]. | ||
| + | |||
| + | == Characteristics == | ||
| + | |||
| + | All uraninite minerals contain a small amount of [[radium]] as a [[radioactive decay]] product of uranium; it was in pitchblende from the [[Jáchymov]] (then also known as Joachimsthal) in [[Czechoslovakia]] that [[Maria Sklodowska-Curie|Marie Curie]] discovered radium. Uraninite also always contains small amounts of the lead [[isotope]]s, Pb-206 and Pb-207, the end products of the decay series of the uranium isotopes U-238 and U-235 respectively. Small amounts of [[helium]] are also present in uraninite as a result of [[alpha decay]]. Helium was first discovered on Earth in uraninite after previously being discovered [[spectroscopy|spectroscopically]] in the [[Sun]]'s atmosphere. The extremely rare element [[technetium]] can be found in uraninite in very small quantities (about 0.2 ng/kg), produced by the spontaneous [[Nuclear fission|fission]] of uranium-238. | ||
| + | |||
| + | == See also == | ||
| + | |||
| + | * [[Radium]] | ||
| + | * [[Uranium]] | ||
==References== | ==References== | ||
| − | |||
| − | + | * Klein, Cornelis, and Barbara Dutrow. 2007. ''Manual of Mineral Science''. 23rd ed. New York: John Wiley. ISBN 978-0471721574. | |
| − | *[ | + | |
| + | * Pellant, Chris. 2002. ''Rocks and Minerals''. Smithsonian Handbooks. New York: Dorling Kindersley. ISBN 0789491060. | ||
| + | |||
| + | * Shaffer, Paul R., Herbert S. Zim, and Raymond Perlman. 2001. ''Rocks, Gems and Minerals''. Rev. ed. New York: St. Martin's Press. ISBN 1582381321. | ||
| + | |||
| + | * Mineral Gallery. 2006. [http://mineral.galleries.com/minerals/oxides/uraninit/uraninit.htm The Mineral Uraninite.] ''Amethyst Galleries''. Retrieved May 14, 2007. | ||
==External links== | ==External links== | ||
| − | + | * [http://www.mindat.org/min-4102.html Uraninite.] ''Mindat.org''. Retrieved May 14, 2007. | |
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| + | [[Category:Minerals]] | ||
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Revision as of 21:38, 14 May 2007
| Uraninite | |
|---|---|
 |
|
| General | |
| Category | Mineral |
| Chemical formula | uranium oxide, UO2 |
| Identification | |
| Color | Black or brownish |
| Crystal habit | Massive, botryoidal, granular. Crystals uncommon. |
| Crystal system | Isometric |
| Cleavage | Indistinct |
| Fracture | Conchoidal to uneven |
| Mohs Scale hardness | 5 - 6 |
| Luster | Submetallic, greasy |
| Refractive index | Opaque |
| Pleochroism | None |
| Streak | Same as color, black or brownish |
| Specific gravity | 7.5 - 10 |
| Solubility | Soluble in sulfuric, nitric, and hydrofluoric acids. |
| Major varieties | |
| Pitchblende | Massive |
Uraninite is a uranium-rich mineral with a composition that is largely UO2 (uranium dioxide), but which also contains UO3 and oxides of lead, thorium, and rare earths. It is most commonly known in the variety pitchblende (from pitch, because of its black color, and blende, a term used by German miners to denote minerals whose weight suggested metal content, but whose exploitation was, at the time they were named, either impossible or not economically feasible).
Occurrence
Uraninite is a major ore of uranium. An important occurrence of pitchblende is at Great Bear Lake in the Northwest Territories of Canada, where it is found in large quantities associated with silver. Some of the highest grade uranium occurrences in the world occur in the Athabasca Basin in northern Saskatchewan. It also occurs in Australia, Germany, England, and South Africa, and in New Hampshire, Connecticut, North Carolina, Wyoming, Colorado and New Mexico in the United States.
Characteristics
All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium; it was in pitchblende from the Jáchymov (then also known as Joachimsthal) in Czechoslovakia that Marie Curie discovered radium. Uraninite also always contains small amounts of the lead isotopes, Pb-206 and Pb-207, the end products of the decay series of the uranium isotopes U-238 and U-235 respectively. Small amounts of helium are also present in uraninite as a result of alpha decay. Helium was first discovered on Earth in uraninite after previously being discovered spectroscopically in the Sun's atmosphere. The extremely rare element technetium can be found in uraninite in very small quantities (about 0.2 ng/kg), produced by the spontaneous fission of uranium-238.
See also
ReferencesISBN links support NWE through referral fees
- Klein, Cornelis, and Barbara Dutrow. 2007. Manual of Mineral Science. 23rd ed. New York: John Wiley. ISBN 978-0471721574.
- Pellant, Chris. 2002. Rocks and Minerals. Smithsonian Handbooks. New York: Dorling Kindersley. ISBN 0789491060.
- Shaffer, Paul R., Herbert S. Zim, and Raymond Perlman. 2001. Rocks, Gems and Minerals. Rev. ed. New York: St. Martin's Press. ISBN 1582381321.
- Mineral Gallery. 2006. The Mineral Uraninite. Amethyst Galleries. Retrieved May 14, 2007.
External links
- Uraninite. Mindat.org. Retrieved May 14, 2007.
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