perovskite

views updated May 08 2018

perovskite A mineral oxide CaTiO3; sp. gr. 3.98–4.26; hardness 5.5; monoclinic or orthorhombic; tiny, cubic crystals; yellow-brown to black; common accessory mineral in undersaturated (see SILICA SATURATION) alkaline igneous rocks found with nepheline or melilite. Occasionally occurs in some ultramafic (see ULTRABASIC), plutonic, igneous rocks.

perovskite model

views updated May 08 2018

perovskite model A theoretical model of the Earth's composition suggesting that the mineral perovskite (CaTiO3) makes up most of the lower part of the mantle between 600 and 2800 km depth, at 2000–2500°C. Perovskite has been made artificially by compressing olivine, pyroxene, and garnet, and has been shown to withstand temperatures of 2000°C in the laboratory.

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