Majorite
Majorite is a type of garnet mineral found in the upper mantle of the Earth. Its chemical formula is Mg3(MgSi)(SiO4)3. It is distinguished from other garnets in having Si in octahedral as well as tetrahedral coordination. Majorite was first described in 1970 from the Coorara Meteorite of Western Australia and has been reported from various other meteorites in which majorite is thought to result from an extraterrestrial high pressure shock event. Mantle derived xenoliths containing majorite have been reported from potassic ultramafic magmas on Malaita Island on the Ontong Java Plateau Southwest Pacific.