AskDefine | Define pitchblende

Dictionary Definition

pitchblende n : a mineral consisting of uranium oxide and trace amounts of radium and thorium and polonium and lead and helium; uraninite in massive form is called pitchblende which is the chief uranium ore [syn: uraninite]

User Contributed Dictionary

English

Noun

  1. A variety of the mineral uraninite.

Translations

  • Finnish: pikivälke
  • German: Pechblende
  • Italian: pechblenda

Extensive Definition

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 density suggested metal content, but whose exploitation was, at the time they were named, either impossible or not economically feasible). All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium; it was in pitchblende from the Jáchymov (then Joachimsthal, Austria-Hungary) now in the Czech Republic 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 found 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.
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 ores in the world have been found in the Athabasca Basin in northern Saskatchewan. It also occurs in Australia, Germany, England, and South Africa. In the United States it can be found in the states of New Hampshire, Connecticut, North Carolina, Wyoming, Colorado and New Mexico.

References

pitchblende in German: Uraninit
pitchblende in Spanish: Pechblenda
pitchblende in French: Pechblende
pitchblende in Indonesian: Pitchblende
pitchblende in Italian: Uraninite
pitchblende in Japanese: 閃ウラン鉱
pitchblende in Latvian: Uraninīts
pitchblende in Lithuanian: Uraninitas
pitchblende in Hungarian: Uránszurokérc
pitchblende in Dutch: Uraniniet
pitchblende in Norwegian Nynorsk: Bekblende
pitchblende in Polish: Uraninit
pitchblende in Portuguese: Pechblenda
pitchblende in Russian: Настуран
pitchblende in Finnish: Uraniitti
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