Complete Slice of a Seymchan Meteorite

"EXTRATERRESTRIAL GEMSTONES IN A METALLIC MATRIX"

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, 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 throughout the slice 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.

REFERENCES:

Meteoritical Bulletin Entry for Seymchan