Wadsleyite

Wadsleyite is a mineral from the mantle and some meteorites. It is an ultra high pressure olivine polymorph (Mg,Fe)₂SiO₄. Wadsleyite is a monoclinic mineral with a more compact structure than orthorhombic olivine resulting from the enormous pressures it has been subjected to. Its stability domain lies between 14 and 20 gigapascals (410 and 550 km deep). Beyond these pressures it is becomes ringwoodite, another polymorph.