Pallasite meteorite

A stony-iron meteorite composed essentially of large single glassy crystals of olivine (forsterite) embedded in a network of nickel-iron, with accessory troilite, chromite, phosphide, various phosphate minerals, and sometimes pyroxene. Pallasites are believed to have been formed at the interface of the stony mantle and metal core of layered planetoids. For a long time, pallasites have been divided into two groups, Main Group (MGP) and the Eagle Station grouplet (PES), based on their oxygen isotopic signatures and forsterite compositions. However, with the new millennium came not only new pallasite samples, but new pallasite subtypes. Thus, in only a few years, the number of pallasite parent bodies has increased from two to five isotopically and/or mineralogically distinct objects, with Scott (2007) suggesting as many as seven.