Ringwoodite

Ringwoodite is a mineral from the mantle and some meteorites. It is an ultra high pressure olivine polymorph (Mg,Fe)₂SiO₄. Ringwoodite is a cubic mineral with a spinel structure. This compact structure means that ringwoodite is stable at 20 to 24 gigapascals (at a depth of 550 km to 670 km). Beyond these pressures ringwoodite decomposes into (Mg,Fe)SiO₃ with a perovskite structure and into magnesiowüstite (Mg,Fe)O.