Northwest Africa 11289
Found in Morocco, 2012
NWA 11289 was found in Morocco and was originally classified as IIIE. This was later changed to IIIAB, the chemical class belonging to coarse octahedrites. Large asteroids with molten cores produced the raw material for iron meteorites, following collisions within the asteroid belt. Extremely slow cooling of those cores, over millions of years, allowed nickel-iron alloys in these meteorites to crystallize into fantastic geometric structures known as Widmanstätten Patterns. NWA 11289 exhibits a highly geometric pattern; octahedrites derive their name from their pattern, which parallels an octahedron. Different iron meteorites are subdivided according to their nickel content, and in octahedrites, that nickel concentration caused bands of nickel-iron alloy to form bands, which are visible when acid etched and polished.