Northwest Africa 14492 (NWA 14492)

Morocco

Purchased: April 2021

Classification: Pallasite (Main group)

History: Robert Cucchiara and Ruben Garcia purchased several kilos of this material from Adam Aaronson at the April gem show in Tucson 2021.

Physical characteristics: The meteorite consists of nine pieces: 1710, 1313, 962, 411, 376, 180, 148, 99, and 60 g. The surface is irregular, with visible cm-scale olivine crystals. Terrestrial alteration is evident on the surface and along grain boundaries extending into the interior.

Petrography: (C. Herd and P. Hill, UAb) Optical examination of polished slices show angular to subrounded olivine grains ranging from sub-mm to cm in size irregularly distributed in a homogenous metal phase. Sulfide inclusions were noted but not analyzed. Standfieldite was identified by EDS during electron microprobe examination.

Geochemistry: (C. Herd and A. Locock, UAb) Data obtained by EMP examination of carbon-coated polished section: Olivine Fa_10.8±0.1 (n=17). ICP-MS data obtained from metallic portion, using sample of North Chile (Filomena) as standard (C. Herd, P. Hill, and S. DuFrane UAb): Ni = 10.2, Co = 0.366 (both wt%); Ir = 0.04, Ga = 11.2, As = 10, Sb = 0.16, Ru = 0.6, Pt = 1.1, Cu = 117, Au = 0.37 (all μg/g). W concentration was below detection (<0.1 ppb). Au value is a minimum due to uncertainties associated with the solution ICP-MS method.

Classification: (C. Herd, UAb): Pallasite, PMG, based on Fa content of olivine and especially Ni, Ir, Ga, Pt, W, Cu, and Sb in metal, through comparison with Wasson and Choi (2003). Au in metal appears to have been underestimated (did not remain in solution).

Specimens: Type specimen consisting of 20.9 g in four representative specimens at UAb. Majority of specimens with Robert Cucchiara and Ruben Garcia; additional specimens with R. Ward and DPitt.