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 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.