19 - A Remarkable Muonionalusta Meteorite Sphere

A Remarkable Muonionalusta Meteorite Sphere Since the vast majority of iron meteorites often have an unremarkable shape, grinding them into a sphere offers an opportunity to reveal their inner crystalline splendor. The sphere has been polished, and acid etching has revealed the striking geometric crystal pattern, known as the “Widmanstätten pattern”, which formed through extremely slow cooling over millions of years within the core of an asteroid. Weight: ca. 1,815 gram LOCATION: Norrbotten 67°48′N 23°6.8′E Diam. ca. 10 cm. PROVENANCE: German Private Collection. This Muonionalusta meteorite comes with a certificate of meteorite identification from the University of Alberta and is signed by dr. Christopher Herd, professor and curator of the University of Alberta Meteorite Collection. NOTE: – The Muonionalusta Meteorite fell to earth during the Quaternary Period, about one million years ago in what is now northern Sweden. Ita came down near the Muonio River for which the meteorite was named. The strewn field sits approximately 140 kilometres (87 miles) north of the Arctic Circle next to the village of Kitkiöjärvi in Norrbotten County, near the border of Sweden and Finland. Possessing what is among the highest terrestrial ages of any meteorite, making it one of the oldest meteorite impacts recorded on Earth. – It was back in 1906 that children discovered the first Muonionalusta meteorite while engaging in the pastime of kicking rocks — and finding one they couldn’t readily kick. – The Muonionalusta iron meteorite, estimated to be around 4.56 billion years old and classified as fine octahedrite type IVA (Of), made of about 91% iron and 8.4% nickel, along with trace amounts of cobalt, gallium, germanium, and iridium. It also contains ‘Stishovite’, a high pressure polymorph of SiO2, and is an exceptionally rare mineral. It has only been found in association with a few meteorite impact structures. Clearly, the meteoritic stishovite cannot have formed by isostatic pressure prevailing in the core of the parent asteroid. One can safely assume then that stishovite formation (in the Muonionalusta meteorite) is connected with an impact event. The glass component might have formed directly as a shock melt.... – The here offered meteorite is a Polished and acid-etched sphere reveal a striking geometric crystal pattern, the so-called famous ‘Widmanstätten Pattern’, caused by cooling very slowly over millions of years in an asteroid core.