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:''This article is about the mineral; for synthetic compounds see perovskite structure.'' Perovskite (''pronunciation:'' ) is a calcium titanium oxide mineral composed of calcium titanate, with the chemical formula CaTiO3. The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856).〔 It lends its name to the class of compounds which have the same type of crystal structure as CaTiO3 (XIIA2+VIB4+X2−3) known as the perovskite structure. The perovskite crystal structure was first described by Victor Goldschmidt in 1926, in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. == Occurrence == Found in the Earth’s mantle, perovskite’s occurrence at Khibina Massif is restricted to the under-saturated ultramafic rocks and foidolites, due to the instability in a paragenesis with feldspar. Perovskite occurs as small anhedral to subhedral crystals filling interstices between the rock-forming silicates.〔 Perovskite is found in contact carbonate skarns at Magnet Cove, Arkansas, in altered blocks of limestone ejected from Mount Vesuvius, in chlorite and talc schist in the Urals and Switzerland.〔Palache, Charles, Harry Berman and Clifford Frondel, 1944, ''Dana's System of Mineralogy'' Vol. 1, Wiley, 7th ed. p. 733〕 and as an accessory mineral in alkaline and mafic igneous rocks, nepheline syenite, melilitite, kimberlites and rare carbonatites. Perovskite is a common mineral in the Ca-Al-rich inclusions found in some chondritic meteorites.〔 A rare earth-bearing variety, ''knopite,'' (Ca,Ce,Na)(Ti,Fe)O3) is found in alkali intrusive rocks in the Kola Peninsula and near Alnö, Sweden. A niobium-bearing variety, ''dysanalyte,'' occurs in carbonatite near Schelingen, Kaiserstuhl, Germany.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「perovskite」の詳細全文を読む スポンサード リンク
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