Steel-black to velvet-black, brownish black, pale gray to pale green; in transmitted light, pale green, pale yellow to deep brown and green-gray (thin fragments)
Uraninite used to be known as pitchblende (from pitch, because of its black color, and blende, from blenden meaning "to deceive", a term used by German miners to denote minerals whose density suggested metal content, but whose exploitation, at the time they were named, was either unknown or not economically feasible). The mineral has been known since at least the 15th century, from silver mines in the Ore Mountains, on the German/Czech border. The type locality is the historic mining and spa town known as Joachimsthal, the modern-day Jáchymov, on the Czech side of the mountains, where F. E. Brückmann described the mineral in 1772.[4][6] Pitchblende from the Johanngeorgenstadt deposit in Germany was used by M. Klaproth in 1789 to discover the element uranium.[7]
All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium. Marie Curie used pitchblende, processing tons of it herself, as the source material for her isolation of radium in 1910.[8]
Uraninite also always contains small amounts of the lead isotopes206Pb and 207Pb, the end products of the decay series of the uranium isotopes 238U and 235U respectively. Small amounts of helium are also present in uraninite as a result of alpha decay. Helium was first found on Earth in cleveite, an impure radioactive variety of uraninite, after having been discovered spectroscopically in the Sun's atmosphere. The extremely rare elements technetium and promethium can be found in uraninite in very small quantities (about 200 pg/kg and 4 fg/kg respectively), produced by the spontaneous fission of uranium-238. Francium can also be found in uraninite at 1 francium atom for every 1 × 1018 uranium atoms in the ore as a result from the decay of actinium.
Occurrenceedit
Uraninite crystals from Topsham, Maine (size: 2.7 × 2.4 × 1.4 cm)
^ abKlein, Cornelis and Cornelius S. Hurlbut, Jr., Manual of Mineralogy, Wiley, 1985, 20th ed. pp. 307–308 ISBN0-471-80580-7
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Uraninite". Handbook of Mineralogy(PDF). Vol. III (Halides, Hydroxides, Oxides). Chantilly, VA: Mineralogical Society of America. ISBN0-9622097-2-4. (PDF) from the original on March 14, 2012. Retrieved December 5, 2011.
^Uraninite October 21, 2011, at the Wayback Machine. Webmineral.com
^Veselovsky, F., Ondrus, P., Gabsová, A., Hlousek, J., Vlasimsky, P., Chernyshew, I. V. (January 2003). "Who was who in Jáchymov mineralogy II" (PDF). Journal of the Czech Geological Society. 48 (3–4): 193–205. (PDF) from the original on April 23, 2014.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Schüttmann, W. (1998). "Das Erzgebirge und sein Uran". RADIZ-Information. 16: 13–34.
^"Marie Curie and the Science of Radioactivity". history.aip.org. from the original on June 28, 2017. Retrieved June 29, 2017.
External linksedit
Media related to Uraninite at Wikimedia Commons
April 07, 2024
uraninite, pitchblende, redirects, here, other, uses, pitchblende, disambiguation, also, known, pitchblende, radioactive, uranium, rich, mineral, with, chemical, composition, that, largely, because, oxidation, typically, contains, variable, proportions, u3o8, . Pitchblende redirects here For other uses see Pitchblende disambiguation Uraninite also known as pitchblende is a radioactive uranium rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8 Radioactive decay of the uranium causes the mineral to contain oxides of lead and trace amounts of helium It may also contain thorium and rare earth elements 2 4 UraninitePitchblende from Niederschlema Alberoda deposit GermanyGeneralCategoryOxide mineralsFormula repeating unit Uranium dioxide or uranium IV oxide UO2 IMA symbolUrn 1 Strunz classification4 DL 05Crystal systemIsometricCrystal classHexoctahedral m3 m H M symbol 4 m 3 2 m Space groupFm3 mUnit cella 5 4682 A Z 4IdentificationColorSteel black to velvet black brownish black pale gray to pale green in transmitted light pale green pale yellow to deep brown and green gray thin fragments Crystal habitMassive botryoidal granular Octahedral crystals uncommon CleavageIndistinctFractureConchoidal to unevenMohs scale hardness5 6LusterSubmetallic greasy dullStreakBrownish black gray olive greenDiaphaneityOpaque transparent in thin fragmentsSpecific gravity10 63 10 95 decreases on oxidationOptical propertiesIsotropicOther characteristicsRadioactive 70 Bq g to 150 kBq gReferences 2 3 4 5 Major varietiesPitchblendeMassive Contents 1 Overview 2 Occurrence 3 See also 4 References 5 External linksOverview editUraninite used to be known as pitchblende from pitch because of its black color and blende from blenden meaning to deceive a term used by German miners to denote minerals whose density suggested metal content but whose exploitation at the time they were named was either unknown or not economically feasible The mineral has been known since at least the 15th century from silver mines in the Ore Mountains on the German Czech border The type locality is the historic mining and spa town known as Joachimsthal the modern day Jachymov on the Czech side of the mountains where F E Bruckmann described the mineral in 1772 4 6 Pitchblende from the Johanngeorgenstadt deposit in Germany was used by M Klaproth in 1789 to discover the element uranium 7 All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium Marie Curie used pitchblende processing tons of it herself as the source material for her isolation of radium in 1910 8 Uraninite also always contains small amounts of the lead isotopes 206Pb and 207Pb the end products of the decay series of the uranium isotopes 238U and 235U respectively Small amounts of helium are also present in uraninite as a result of alpha decay Helium was first found on Earth in cleveite an impure radioactive variety of uraninite after having been discovered spectroscopically in the Sun s atmosphere The extremely rare elements technetium and promethium can be found in uraninite in very small quantities about 200 pg kg and 4 fg kg respectively produced by the spontaneous fission of uranium 238 Francium can also be found in uraninite at 1 francium atom for every 1 1018 uranium atoms in the ore as a result from the decay of actinium Occurrence edit nbsp Uraninite crystals from Topsham Maine size 2 7 2 4 1 4 cm Uraninite is a major ore of uranium Some of the highest grade uranium ores in the world were found in the Shinkolobwe mine in the Democratic Republic of the Congo the initial source for the Manhattan Project and in the Athabasca Basin in northern Saskatchewan Canada Another important source of pitchblende is at Great Bear Lake in the Northwest Territories of Canada where it is found in large quantities associated with silver It also occurs in Australia the Czech Republic Germany England Rwanda Namibia and South Africa In the United States it can be found in the states of Arizona Colorado Connecticut Maine New Hampshire New Mexico North Carolina and Wyoming The geologist Charles Steen made a fortune on the production of uraninite in his Mi Vida mine in Moab Utah Uranium ores from the Ore Mountains today the border between the Czech Republic and Germany were an important supply of both the wartime German nuclear program which failed to produce a bomb and the Soviet nuclear program Mining for uranium in the Ore Mountains under the auspices of SDAG Wismut after the war ceased after the collapse of the German Democratic Republic Uranium ore is generally processed close to the mine into yellowcake which is an intermediate step in the processing of uranium See also editList of minerals List of uranium mines Thorianite Uranium ore depositsReferences edit Warr L N 2021 IMA CNMNC approved mineral symbols Mineralogical Magazine 85 3 291 320 Bibcode 2021MinM 85 291W doi 10 1180 mgm 2021 43 S2CID 235729616 a b Klein Cornelis and Cornelius S Hurlbut Jr Manual of Mineralogy Wiley 1985 20th ed pp 307 308 ISBN 0 471 80580 7 Anthony John W Bideaux Richard A Bladh Kenneth W Nichols Monte C eds Uraninite Handbook of Mineralogy PDF Vol III Halides Hydroxides Oxides Chantilly VA Mineralogical Society of America ISBN 0 9622097 2 4 Archived PDF from the original on March 14 2012 Retrieved December 5 2011 a b c Uraninite Archived November 10 2012 at the Wayback Machine Mindat org Uraninite Archived October 21 2011 at the Wayback Machine Webmineral com Veselovsky F Ondrus P Gabsova A Hlousek J Vlasimsky P Chernyshew I V January 2003 Who was who in Jachymov mineralogy II PDF Journal of the Czech Geological Society 48 3 4 193 205 Archived PDF from the original on April 23 2014 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link Schuttmann W 1998 Das Erzgebirge und sein Uran RADIZ Information 16 13 34 Marie Curie and the Science of Radioactivity history aip org Archived from the original on June 28 2017 Retrieved June 29 2017 External links edit nbsp Media related to Uraninite at Wikimedia Commons Retrieved from https en wikipedia org w index php title Uraninite amp oldid 1217536046, wikipedia, wiki, book, books, library,
