Northwest Africa 6903 (NWA 6903)        32°22.3’N, 6°21.6’W

Centre, Morocco

Purchased: 2008

Classification: Iron meteorite (IIIAB)

History: Purchased near side of road near Khouribga, Morocco.

Physical characteristics: Heavy weathering around the perimeter and along a crack; near one edge oxidation penetrates about 1 cm into the interior, with kamacite largely replaced by oxides in fields of fine plessite.

Petrography: (J.T. Wasson, UCLA): Medium octahedrite, band-width 1.2 mm. Schreibersite is present in the interiors of larger kamacite bands; a typical size is 2 × 0.3 mm. No FeS was observed.

Geochemistry: Compositional data: Co 5.2 mg/g; Ni 84 mg/g; Ga 21.5 μg/g; Ge <50 μg/g; As 8.8 μg/g; Ir 0.22 μg/g; Au 1.09 μg/g. Data are the mean of duplicate determinations.

Classification: The meteorite is a member of IIIAB. Its composition is near the center of this largest group of irons. There is no compositional evidence of pairing. If compared to IIIABs with Au compositions between 1.04 and 1.14 mg/g there is only one other irons with Ir contents within 15% of that of this iron (Pozo Almonte). Thus, this is probably an independent fall.

Specimens: 318.7 g, UCLA; main mass, Aaronson