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. The properties of mantle perovskites strongly influence the transport properties of rocks in the lower mantle. Perovskites are expected to occur throughout the universe as an important constituent of rocky planets larger than Mars.