Seymchan Meteorite End Piece

A SUBSTANTIAL PORTION OF A FAMOUS RUSSIAN PALLASITE

Pallasites represent less than 0.2% of all known meteorites and are widely considered to be the most beautiful extraterrestrial substances known. Like the vast majority of pallasitic meteorites, Seymchan originated from the mantle-core boundary of an asteroid that broke apart during the early history of our solar system. Following pinball-like ricochets, a portion was serendipitously bumped into an Earth-crossing orbit.

The crystals seen here are the result of small chunks of the asteroid's stony mantle becoming suspended and crystallized in the molten metal of its iron-nickel core. Cut and polished on one side, the lustrous metallic matrix features silicate crystals of gleaming olivine and peridot (gem-quality olivine) ranging in color from shimmering gold and amber to deep sea green. The prominent metallic latticework found on the cut side of this Seymchan end piece is referred to as a Widmanstätten pattern and is the result of slow cooling over millions of years, providing sufficient time for the two iron-nickel alloys present in the meteorite to orient into a crystalline habit. As Widmanstätten patterns can only occur within differentiated asteroids in the vacuum of space, their presence is diagnostic in the identification of a meteorite. In addition, as its crystals are scattered irregularly throughout the metallic matrix, Seymchan is referred to as a transitional pallasite, a much less common and more distinct variety of an already exceedingly rare type of meteorite.

The uncut side of this Seymchan end piece reveals the natural crests and grooves of the exterior of this stony-iron meteorite — a wonderful juxtaposition to the gorgeous gemstones and shining metal found inside.

REFERENCES:

Meteoritical Bulletin Entry for Seymchan