This is an end piece of the 5549th meteorite to be catalogued following its recovery in the North West African grid of the Sahara Desert. In the vast majority of iron meteorites, silicate inclusions are absent, but not in the IAB group. And it is certainly not the case for NWA 5549, where silicates are plentiful and seen in the cut and polished face as rounded inclusions, sharp-angled fragments and small grains. Whereas the vast majority of iron meteorites crystallized within the molten metal cores of asteroids, the IAB group appears to have formed in the near-surface region of a chondritic asteroid following a massive impact event that caused partial separation of metal and silicate.

The cut surface reveals silicates interspersed in a matrix featuring a coarse Widmanstätten pattern which shimmers when rocked from side to side. The presence of this latticework is diagnostic in the identification of iron meteorites, and meteorites from different groups exhibit different crystalline patterns as a result of their varying compositions and cooling rates. The furrowed, highly textured reverse exterior evidences the aerodynamic scalloping referred to as regmaglypts (i.e., “thumb prints”), the result of melting from frictional heating as the meteorite plunged through Earth’s atmosphere.

Christie's would like to thank Dr. Alan E. Rubin at the Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles for his assistance in preparing this catalogue.


117 x 157 x 23mm (4.66 x 6 x 1 in.) and 897.6g (2 lbs)