Northwest Africa 8302 (NWA 8302)

(Northwest Africa)

Purchased: 2010

Classification: Iron meteorite (IIAB)

Petrography: A 139 g piece of the type specimen shows a typical hexahedrite structure. Inclusions are common but small. Most are FeS, 1-3 mm in long dimension, and always surrounded by schreibersite. Oxidation is minor, and mainly at inclusion boundaries; there may be a heat-altered zone but better sample prep is needed to confirm this. There are parallel 1 mm thick bands crossing the specimen, which may be shear zones that were later annealed.

Geochemistry: Composition: Co, 4.54 mg/g; Ni, 57.0 mg/g; Ga, 59.6 μg/g; Ge, <250 μg/g; As, 4.6 μg/g Ir, 7.6 μg/g; and Au, 0.59 μg/g. No close NWA relatives; nearest in Ir is NWA 3202 with 11.4 μg/g.