Iron meteorite, fine octahedrite - IVA, Kiruna, Sweden
Found above the Arctic Circle near the Muonio River in northern Sweden, Muonionalusta meteorites have been on Earth longer than most. Originating from the core of an asteroid between Jupiter and Mars, Muonionalusta fell to Earth about one million years ago. Had it not fallen in Northern Sweden but, say, New York, and if it stayed in the ground it would have slowly terrestrialized and disintegrated long before one million years passed — but Muonionalusta landed in what is among Earth’s coldest freezers.
Almost all Muonionalusta meteorites are subdivided to reveal the magic within because from the outside they typically look like common boulders. Referred to as glacial erratics, they tumbled again and again in one of Earth’s largest rock tumblers over four different ice ages. Like most iron meteorites Muonionalusta contains a relatively a large amount of iridium which is among the most rust resistant metals known — and it contains more than most iron meteorites. It was the presence of 100x more iridium than is typically found in Earth’s crust at the K-T Boundary (the transition between the Cretaceous and Tertiary geological formations) which gave rise to the theory that it was an iron asteroid which killed-off the dinosaurs…providing the opportunity for human life to evolve. Yes, we are here because of a meteorite impact.
When sliced and etched, Muonionalusta showcases the resplendent crystalline structure of its two iron-nickel alloys, kamacite and taenite. This matrix is diagnostic in the identification of an iron meteorite and different meteorites from different parent bodies have different patterns. As Gibeon meteorites have the same pattern and are compositionally the same as Muonionalusta, we can infer they are siblings; it just took Gibeons about a million years longer to arrive here.
The cut and face of this particular meteorite has a rather fascinating accent of plessite with Neumann bands arcing through the mass. Plessite is fine grained kamacite and taenite which did not develop into the crystalline lattice otherwise seen. Neumann bands from an extremely high velocity impact with another asteroid are seen. The reverse has a natural silvery patina as a result of having been cleaned — a hue closely to how it appeared before burning through the atmosphere. Exhibiting a shimmering latticework of its crystalline structure, and with quite a story — both on and off Earth — this exemplary Muonionalusta end piece is accompanied by a custom armature.
198 x 75 x 41mm (7.75 x 3 x 1.66 in.) and 1377.8 grams (3 lbs)
