thorianite

thorianite
/thawr"ee euh nuyt', thohr"-/, n.
a rare mineral, mainly thoria, ThO2, but also containing uranium, cerium, and other rare-earth metals, occurring in small, black, cubic crystals: notable for its radioactivity and used as a minor source of thorium.
[1900-05; thorian (THORI(A) + -AN) + -ITE1]

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      thorium dioxide mineral (ThO2) that is very heavy, hard, and coloured dark gray to brownish black or bluish black. Originally found as waterworn grains and crystals in the gem gravels of Ceylon (now Sri Lanka), thorianite also occurs sparsely in the black river and beach sands of Alaska, Madagascar, and Siberia. The refractory nature and scarcity of thorianite have restricted its commercial use as a source of thorium. It forms a solid-solution series with uraninite in which uranium atoms replace thorium atoms in the crystal structure. Rare earths and radiogenic lead and helium are often present. Varieties containing much uranium have been found in pegmatites in Quebec and Ontario and in serpentine at Easton, Pa. For detailed physical properties, see oxide mineral (table).

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Universalium. 2010.

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  • thorianite — ● thorianite nom féminin (de thorium) Oxyde naturel d uranium et de thorium, de formule (Th,U)O2, de couleur noir de jais, cubique. thorianite [tɔʀjanit] n. f. ÉTYM. 1905, in Rev. gén. des sc., no 12, p. 585; de thor(ium), (ur)an(ium), et ite. ❖ …   Encyclopédie Universelle

  • thorianite — [thôr′ē ənīt΄] n. [< THORIA + ITE1] a grayish to black, very hard, radioactive mineral, thorium dioxide, ThO2, that is an ore of thorium …   English World dictionary

  • Thorianite — Infobox mineral name = Thorianite category = boxwidth = boxbgcolor = imagesize = caption = formula = Thorium oxide, ThO2 molweight = color = Dark gray, brown black habit = Rounded grains system = Isometric twinning = Penetration twins on {111}… …   Wikipedia

  • Thorianite — Cristaux de thorianite de Madagascar (1,6 x 1,4 x 1,3 cm) La thorianite est une espèce minérale, formée d oxyde de thorium de formule Th O2 avec des traces de U;Ce;La;Pb;TR. Variétés Aldanite une variété contenant de 14.9% à 29.0% de UO2 et 11.2% …   Wikipédia en Français

  • thorianite — torianitas statusas T sritis chemija apibrėžtis Mineralas. formulė (Th,U)O₂ atitikmenys: angl. thorianite rus. торианит …   Chemijos terminų aiškinamasis žodynas

  • thorianite — noun Etymology: irregular from thoria Date: 1904 a strongly radioactive mineral that is an oxide of thorium and often contains rare earth elements …   New Collegiate Dictionary

  • thorianite — noun A radioactive mineral containing thorium dioxide (ThO) plus oxides of uranium, lanthanum, cerium neodymium and praseodymium in smaller quantities …   Wiktionary

  • thorianite — tho·ri·a·nite …   English syllables

  • thorianite — tho•ri•a•nite [[t]ˈθɔr i əˌnaɪt, ˈθoʊr [/t]] n. mir a rare, black, radioactive mineral, mainly thoria, ThO2, usu. found mixed with uranium, dioxide, and rare earth metals: a minor source of thorium • Etymology: 1900–05; thorian (thori ( a) + an… …   From formal English to slang

  • thorianite — /ˈθɔriəˌnaɪt/ (say thawreeuh.nuyt) noun a rare mineral, mainly thorium oxide, ThO2, but containing also uranium, cerium, etc., occurring in small, black, cubic crystals, notable for its radioactivity. {thor(ium) + ian + ite2} …  

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