Northwest Africa 12000 (NWA 12000)

Morocco

Purchased: May 2017

Classification: Iron meteorite (IIAB)

History: Purchased by Zhang Qingyan in May 2017 from a Moroccan dealer during the China (Hunan) Mineral & Gem Show in Chenzhou City

Physical characteristics: The main mass is approximately 2 × 5 × 10 cm with a dark brown, regmaglypted exterior. Some rust-red spots and adhered caliche are visible.

Petrography: (C. Herd) A 1 × 2 cm polished and etched slice shows an equant texture of kamacite crystals at least as wide as the slice (1 cm) with interstitial schreibersite. The cm-scale kamacite is replaced by sub-500 μm equant crystals. Neumann lines are present.

Geochemistry: ICP-MS data, using sample of North Chile (Filomena) as standard (C. Herd and G. Chen UAb): Ni = 5.7, Co = 0.49 (both wt%); Cu = 123, Ga = 55, As = 9.5, Ru = 3.4, W = 0.7, Ir = 0.03, Pd = 2.5, Pt = 4.5, Au = 1.1 (all μg/g).

Classification: Iron, IIAB. Recrystallized texture.

Specimens: Type specimen of 24.3 g at UAb. Zhang Qingyan 103 g, Liang Chengguang 28 g, M. Ouzillou 69.3 g.