Seymchan Pallasite Meteorite 740.4 g

Seymchan Pallasite Meteorite 740.4 g

An impressive cut sample of Seymchan pallasite meteorite. The first Seymchan meteorite was found in June of 1967 by geologist F.A. Mednikov in a dry river bed in the Magadan district of Russia, near the town of Seymchan. A second piece was discovered later that year. Seymchan was originally believed to be an iron meteorite, until an expedition in 2004 discovered new specimens which contained olivine crystals. This led to it being reclassified as a pallasite, which is a type of stony-iron meteorite. Out of the three main types of meteorite (stony, stony-iron, and iron), the stony-irons are by far the rarest.

Pallasites are composed of an iron-nickel matrix with silicate inclusions. Usually, the silicates are large olivine crystals with a translucent yellow-green appearance, making pallasites some of the most beautiful meteorites.

The formation of pallasites is a subject of debate among scientists. They were long believed to have come from differentiated asteroids, which are asteroids that have melted, allowing them to separate into a layered structure of core, mantle, and crust. The established theory was that pallasites originate at the boundary between the core and the mantle, where iron from the core is squeezed up into the olivine in the mantle. However, another theory is that there is evidence to suggest they were created by collisions between larger and smaller asteroids. Upon impact, molten iron from the core of the smaller asteroid is injected into the mantle of the larger body, creating the nickel-iron and olivine mixture of pallasites.