Seymchan XXL meteorite Stony-Iron Meteorite - 442 g

Large complete slice of Seymchan Meteorite. healthy matrix without oxidation, olivines not translucent.

Seymchan is a pallasite meteorite found in the dry bed of the Hekandue River, a left tributary of the Jasačnaja River in Magadan District, Russia, near the settlement of Seymchan, in June 1967.

The main mass of 272. 3 kilograms (600 lb) was discovered during a June 1967 survey by geologist FA Mednikov. The mass was a thumbprint triangular meteorite that lay between the stones of the stream bed. A second 51 kilogram (112 lb) specimen was found with a mine detector at a distance of 20 m from the first in October 1967 by IH Markov. The main mass was entrusted to the USSR Academy of Sciences.

During a new expedition in 2004, Dmitri Kachalin recovered around 50 kilograms of new material. Remarkably, about 20% of the new specimens contained olivine crystals, revealing the siliceous nature of the meteorite. The pallasitic structure had not yet been discovered during studies of small sections of the original mass, consisting only of metal.

Seymchan belongs to the main group pallasites, but it is considered anomalous due to its high iridium content. Before the discovery of its pallasitic structure, it had been classified as anomalous coarse octahedrite IIE. Seymchan is considered a stable and rust-resistant pallasite.