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Thorium dioxide (ThO 2), also called thorium(IV) oxide, is a crystalline solid, often white or yellow in colour. Also known as thoria, it is mainly a by-product of lanthanide and uranium production. [4] Thorianite is the name of the mineralogical form of thorium dioxide. It is moderately rare and crystallizes in an isometric system.
Thorianite is a rare thorium oxide mineral, ThO 2. [5] It was originally described by Ananda Coomaraswamy in 1904 as uraninite, [6] but recognized as a new species by Wyndham R. Dunstan. [7] It was so named by Dunstan on account of its high percentage of thorium; it also contains the oxides of uranium, lanthanum, cerium, praseodymium and neodymium.
This is because thorium is likely to form oxide minerals that do not sink into the core; it is classified as a lithophile under the Goldschmidt classification, meaning that it is generally found combined with oxygen. Common thorium compounds are also poorly soluble in water.
Thorium reacts with hydrogen to form the thorium hydrides ThH 2 and Th 4 H 15, the latter of which is superconducting below the transition temperature of 7.5–8 K; at standard temperature and pressure, it conducts electricity like a metal. [12] Thorium is the only metallic element that readily forms a hydride higher than MH 3. [31]
Thorianite is a rare mineral and may contain up to about 12% thorium oxide. Monazite contains 2.5% thorium, allanite has 0.1 to 2% thorium and zircon can have up to 0.4% thorium. [2] Thorium-containing minerals occur on all continents. [3] [4] [5] Thorium is several times more abundant in Earth's crust than all isotopes of uranium combined and ...
In 1839 the third source for rare earths became available. This is a mineral similar to gadolinite called uranotantalum (now called "samarskite") an oxide of a mixture of elements such as yttrium, ytterbium, iron, uranium, thorium, calcium, niobium, and tantalum. This mineral from Miass in the southern Ural Mountains was documented by Gustav Rose.
Minerals containing the chemical element thorium. Pages in category "Thorium minerals" The following 21 pages are in this category, out of 21 total.
Huttonite is a thorium nesosilicate mineral with the chemical formula Th Si O 4 and which crystallizes in the monoclinic system. It is dimorphous with tetragonal thorite, and isostructual with monazite. An uncommon mineral, huttonite forms transparent or translucent cream–colored crystals