Ringwoodite is a high-pressure phase of Mg2SiO4 formed at high temperatures and pressures of the Earth's mantle between 525 and 660 km depth. It may also contain iron and hydrogen. It is polymorphous

The upper mantle of Earth is a very thick layer of rock inside the planet, which begins just beneath the crust and ends at the top of the lower mantle, at about 670 km. Temperatures range from around