Northwest Africa 14495 (NWA 14495)

(Northwest Africa)

Purchased: Feb 2020

Classification: Iron meteorite (IVA)

History: Purchased from Matthew Stream in February 2020, who purchased it from a Moroccan dealer.

Physical characteristics: The single, irregular mass has a mottled dark brown to black, pitted surface.

Petrography: (C. Herd and P. Hill, UAb) Petrographic investigation of a 2 cm × 4.5 cm polished and etched slice shows a well-developed Widmanstaetten pattern consistent with finest octahedrite structural classification (estimated based on photos provided by the owner). No inclusions were observed. No terrestrial alteration is present.

Geochemistry: ICP-MS data, using sample of North Chile (Filomena) as standard (C. Herd, P. Hill, and S. DuFrane UAb): Ni = 8.0, Co = 0.372 (both wt%); Ir = 1.9, Ga = 2.0, Ge = 1.3, As = 5.3, Ru = 4.0, Re = 0.2, Os = 1.5, W = 0.44, Pt = 5.8, Cu = 150, Au = 0.07 (all μg/g). Au value is a minimum due to uncertainties associated with the solution ICP-MS method.

Classification: (C. Herd and P. Hill, UAb): IVA iron, finest octahedrite (estimated). Classification is based on Ni, Co, Ir, Ga, As, W, Pt and Cu, by comparison with Wasson and Richardson (2001). Ge appears to be overestimated, and Au appears to have been underestimated (did not remain in solution).

Specimens: Type specimen consisting of a 23.4 g slice at UAb. Main mass with Shun-Chung Yang.