Superior Seymchan pallasite meteorite slice, demonstrating the transition from an iron structure to an olivine structure. Etched and polished on both sides, the full slice weighs 686.9 grams and measures approximately 230 mm x 180 mm x 3 mm. Nothing better demonstrates the unusual composition and mystifying formation of the Seymchan pallasite than this magnificent full slice, which appears in the shape of a puffer fish. Most known Seymchan specimens are rich in iron, or rich in olivine, but this highly desirable example is described as a transitional specimen, in that it presents both structures. This juxtaposition of differing structures has occasionally been seen in the Brenham (Kansas) and Glorieta Mountain (New Mexico) pallasites, but is extremely rare, especially in a large and complete slice such as this one.
As pallasite meteorites are believed to have formed at the core/mantle boundary of large asteroids there is only a narrow horizon of favorable conditions within these meteorites' parent bodies. That explains why out of approximately 60,000 officially recognized meteorites, there are less than 120 pallasites. The preparation of this meteorite presented special challenges: when sent to one of the foremost labs in the world, the preparator reported it was the single hardest meteorite he had cut in over twenty-five years and required the construction of a special diamond-tipped blade. Each pass of the saw took eight hours (sixteen hours, therefore, per slice), plus polishing and etching. As such, this particular piece benefitted from exceptional care and attention in the laboratory, right down to the etching process which revealed a complex and exquisite lattice-like Widmanstätten pattern. Other slices taken from the same mass have been acquired by prominent museum collections and noted private collectors in various countries. Several experts have gone on record as saying this mass produced the finest transitional slices they had ever seen. In our experience, one of the absolute best examples of its type, also displaying some translucent olivine (peridot) crystals and the rare nickel-iron phosphide mineral, schreibersite. Accompanied by a certificate of authenticity signed by Geoff Notkin of Aerolite Meteorites Inc. and the TV show Meteorite Men, as well as a specimen identification card.
