Pallasite Meteorites

Pallasite meteorites are a rare class of stony-iron meteorites. They were once believed to have originated at the core-mantle boundary of asteroids that shattered through impacts, though a recent hypothesis is that they are a mixture of core and mantle minerals. Pallasite meteorites consist of olivine ( peridot ) crystals surrounded in an iron-nickel matrix. Some pallasites display interweaving structures known as Widmanstätten patterns (or Thomson structures) in areas of coarser metal. These structures are comprised of iron-nickel crystals of the nickel-iron alloys kamacite and taenite.