Seymchan Pallasite Sphere

olivine pallasite crystals seymchan identified meteorites nickel content iron-nickel sphere meteorite kamacite large parts widmanstätten patterns dispersed pattern unique core alloys taenite high higher originally rare containing polished seen bands smaller mirror-bright magadanskaya matrix present distinctive iron allow rate degrees created intersecting used identify contain beautiful revealing rocks resulting district siberia russia gemstones outer space display lovely relatively small specific pressure temperature range slow cooling separation crystalline structure polish literally asteroid million approximately grams pallasites olivines earth parent years weighing 0.67 diameter 48mm