This is the largest and one of the most beautiful stone meteorites ever offered by Christie's at auction. About 73% of the meteorites in collections are ordinary chondrites (hence the name) and these are derived from three separate asteroids. The meteorites are labeled H (high total iron), L (low total iron) and LL (low total iron, low metallic iron). (The total amount of iron includes iron metal and oxidized iron in silicates and oxides.) NWA 8413 is a member of the H-chondrite group and contains abundant metallic iron. Large stone meteorites are extremely rare. Whereas the average mass of an H chondrite find is about 24 g, NWA 8413 is the 20th largest single H chondrite known, with a mass of 155 kg. It was found in Northwest Africa in 2011. The rock has been extensively heated on its parent asteroid; during this thermal metamorphism process, the chondrules were recrystallized and the individual mineral grains became compositionally homogeneous. That heating earned the meteorite the designation of type 6, the highest metamorphic grade.