Ringwoodite

Ringwoodite is the high-pressure polymorph of olivine that is stable at high temperatures and pressures of the Earth's mantle between 525 to 660 km depth. This mineral was first identified in the Tenham Meteorites in 1969, and it is inferred to be present in large quantity in the Earth’s mantle. It was named after the Australian earth scientist Ted Ringwood (1930–1993) who studied polymorphic phase transitions in the common mantle minerals, olivine and pyroxene, at pressures equivalent to depths as great as about 600 km. Olivine, wadsleyite, and ringwoodite are polymorphs found in the upper mantle of the earth. At depths greater than about 660 km; other minerals, including some with the perovskite structure, are stable. The properties of these minerals determine many of the properties of the mantle.