Perovskite

[7] 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).

[8] The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw.

[9] Found in the Earth's mantle, perovskite's occurrence at Khibina Massif is restricted to the silica under-saturated ultramafic rocks and foidolites, due to the instability in a paragenesis with feldspar.

[10] Perovskite is found in contact carbonate skarns at Magnet Cove, Arkansas, US, in altered blocks of limestone ejected from Mount Vesuvius, in chlorite and talc schist in the Urals and Switzerland,[11] and as an accessory mineral in alkaline and mafic igneous rocks, nepheline syenite, melilitite, kimberlites and rare carbonatites.

[12] A rare-earth-bearing variety knopite with the chemical formula (Ca,Ce,Na)(Ti,Fe)O3 is found in alkali intrusive rocks in the Kola Peninsula and near Alnö, Sweden.

[11][13] In stars and brown dwarfs the formation of perovskite grains is responsible for the depletion of titanium oxide in the photosphere.

A large number of metallic elements are stable in the perovskite structure if the Goldschmidt tolerance factor t is in the range of 0.75 to 1.0.

When conditions are not fulfilled, a layered geometry for edge-sharing or face-sharing octahedra or lower B-site coordination is preferred.

[18] Perovskites have sub-metallic to metallic luster, colorless streak, and cube-like structure along with imperfect cleavage and brittle tenacity.

Crystal structure of perovskite CaTiO 3 ; red=oxygen, grey=titanium, blue=calcium