Youndegin Meteorite (USNM 822)

The iron meteorite Youndegin (Australia) contains large dark nodules of troilite and graphite. Youndegin is part of a group of iron meteorites that also contain silicate inclusions similar to chondrites in composition. These features suggest that Youndegin may be the sample of the core of an asteroid formed by relatively small amounts of sulfur-rich metallic melt. The 35-cm long cut face has been polished and etched in acid to reveal the geometric Widmanstätten pattern, which reflects the presence of two different iron-nickel alloys, named kamacite and taenite.