The Discovery of Davemaoite, the CaSiO₃ Perovskite, in a Diamond from Earth’s Lower Mantle

Abstract

Common silicate minerals such as olivine and garnet convert to other phases when brought to great depths in the planet, where they are subjected to extreme pressures. It has long been thought that two of the most common phases at depth in Earth have the perovskite structure. They have long been known from experimental studies in which they have been called magnesium silicate perovskite (MgSiO3) and calcium silicate perovskite (CaSiO3). Only recently has the magnesium silicate perovskite been found in nature, in a meteorite, where it was characterized and named bridgmanite (O. Tschauner et al., “Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite,” Science, Vol. 346, 2014, pp. 1100–1102). More recently, the calcium silicate perovskite has been found in a diamond and sufficiently characterized to be given a mineral species name (O. Tschauner et al., “Discovery of davemaoite, CaSiO3-perovskite, as a mineral from the lower mantle,” Science, Vol. 374, 2021, pp. 891–894).