Iron, fine octahedrite Kiruna, Sweden

Muonionalusta meteorites were found in northern Sweden above the Arctic Circle near the Muonio River. While meteorite hunters have unearthed numerous masses in recent years, it was back in 1906 that children discovered the first Muonionalusta while engaging in a favourite childhood pastime: kicking rocks—and in this instance kicking an unexpectedly dense object later verified to be a meteorite. Possessing what is among the highest terrestrial ages of any meteorite, Muonionalusta fell to Earth about one million years ago when the region was glaciated. Despite its age, many specimens exhibit only minor interior weathering as a result of it being “on ice” in the freezer of the Arctic. Muonionalusta specimens are believed to be glacial erratics (material transported by a glacier), and their exposure to churning rocks and ice during the course of four ice ages would account for the smooth surface of most specimens. It is all about the splendour within; when sliced and etched, Muonionalusta displays the classic Widmanstätten pattern, the intergrowth of two iron-nickel minerals that form an unearthly metallic grid in shimmering shades of gray and silver which is diagnostic in the identification of an iron meteorite.