Welcome to the Astro Gallery of Gems blog. This is our initial voyage into some of the interesting natural history specimens that we get to see all the time. It's pretty cool to hold certain things in your hand, that you know are so rare and beautiful that you feel lucky to be there at this very moment.
We just brought a large quantity of new Meteorites into the Gallery. Collecting these celestial objects is incredibly popular and they come in many different sizes and shapes. We wanted to highlight one type that is very unique in it's look and formation.
This Seymchan meteorite was found in Russia. This rare meteorite slab is unique for many reasons. First, it is transitional between octahedrite and pallasite with a core-mantle border. It shows signs of the core as well as the iron of the meteorite.
The pallasites are a class of stony–iron meteorite. It consists of centimeter-sized olivine crystals of peridot quality in an iron-nickel matrix. Coarser metal areas develop Widmanstätten patterns upon etching. Minor constituents are schreibersite, troilite, chromite, pyroxenes, and phosphates (whitlockite, stanfieldite, farringtonite, and merrillite).
Seymchan meteorites are renowned for some of the most robust crystalline patterns seen, and this large complete slice is, with its shimmering etch, in the tradition of the best examples.
This specimen has a prominent Widmanstätten pattern in evidence; this latticework is indicative of a slow cooling rate that provided sufficient time — millions of years — for the two metallic alloys to form their intricate intergrowth. It is the identification of an iron meteorite.
There are two types of Seymchan specimens - with or without olivine crystals. This specimen has clearly visible crystals throughout the entire left side. The Widmanstatten pattern on the right hand side of the specimen is visibly bent. This is caused by the shearing of the meteorite as it broke up during atmospheric entry and serves as testimony of the violent experience a meteor is subject to as it falls through the atmosphere.
During a Russian expedition in 2004, Dmitri Kachalin recovered about 50 kilograms (110 lb) of this material. Remarkably, about 20% of the new specimens were found to contain olivine crystals, and so revealed the silicated nature of the meteorite. The pallasitic structure was not previously discovered during studies on small metal-only sections of the original mass found in 1964.