1.6" Etched Seymchan Pallasite Slice (23.0 grams) - Russia

The Seymchan meteorite, based on the first few specimens recovered in 1967, was originally classified as a course octahedrite (IIE) iron. Recently, meteorite hunters using metal detectors have recovered many new masses. Several of these (an estimated 10 to 20% of the masses) contain olivine, revealing the true pallasitic nature of this meteorite, leading to its reclassification.

Pallasite meteorites are a class of stony-iron meteorites. They were once believed to have originated at the core-mantle boundary of asteroids that shattered through impacts, though a recent hypothesis is that they are a mixture of core and mantle minerals.

Pallasite meteorites consist of olivine (peridot) crystals that are surrounded in an iron-nickel matrix. Some pallasites will display interweaving structures known as Widmanstätten patterns or Thomson structures in areas of coarser metal. These structures are comprised of iron-nickel crystals commonly in the form of kamacite and taenite.

Less than 100 pallasite meteorites are known, with only four having been documented as observed during their fall.