Pallasites are not only rare, representing less than 0.2% of all known meteorites, they are also widely considered the most beautiful alien substance known. Like all pallasitic meteorites, Seymchan originated at the mantle/core boundary of an asteroid that blasted apart following a cataclysmic collision with another asteroid. The crystals seen here are the result of small chunks of the stony mantle becoming suspended in the molten metal of the core. Cut and polished, the lustrous metallic matrix features crystals of gleaming olivine ranging in hues from emerald to amber. The prominent latticework referred to as a Widmanstätten pattern is indicative of a slow cooling rate that provided sufficient time — millions of years — for the two primary alloys to form the present crystalline structure. This pattern is diagnostic in the identification of an iron meteorite and different iron meteorites have different patterns.

It was in the 1960s that the first masses of Seymchan were found in a streambed in a part of Siberia made infamous as the remote location of Stalin’s gulags. Identified as meteorites, they were named Seymchan for a nearby town. Unlike most pallasites, the dispersion of olivine crystals in Seymchan is extremely heterogeneous. Some specimens are olivine rich and some are olivine poor; some specimens have no olivine whatsoever. The example now offered exhibits discreet clusters of olivine and its gem-quality counterpart, peridot, in select areas of the specimen. It is referred to as being “transitional”, and it could be suggested that this specimen provides the most beguiling attributes of both iron and stony-iron meteorites.