Northwest Africa 13171 (NWA 13171)

Morocco

Purchased: 2017 Jun 18

Classification: Ordinary chondrite (L3)

History: The meteorite was purchased by Bing’an Miao at the China Mineral and Gem Show (CMGS), Chenzhou, China, in 2018.

Physical characteristics: The sample, without fusion crust, has a dark-gray interior with a light-brown surface. The chondrules are clearly visible on the surface, with sizes generally from 1 mm to 3 mm, a few up to 5 mm. It is relative fresh, without visible iron rust on the surface.

Petrography: Under microscopy, the chondrules are well-defined, and they generally range from 0.1 to 3 mm, with an average of 0.74 mm, a few up to 5 mm. The chondrule types include POP, PO, PP, RP, and BO et al. Mesostasis glass is present in porphyritic chondrules. The matrix between the chondrules (12.5 vol%) is opaque and black, without any obvious recrystallization. The Fe-Ni metal, about 3.5 vol%, is dispersed in matrix as fine particles, partially surrounding chondrules. The mineral assemblage is olivine, orthopyroxene, clinopyroxene, kamacite, taenite and troilite.

Geochemistry: Mineral chemistry and geochemistry: Olivine is Fa_21.9±6.2, n=13, low-Ca pyroxene is Fs_19.3±7.8Wo_3±0.5, n=15. Kamacite is Fe 95.4±0.8, Ni4.9±0.9, Co 0.72±0.1, N=11; Taenite is Fe 52.2±4.3, Ni 47.2±3.8, Co 0.2±0.1, N=10; Troilite is Fe 63±0.7, Ni 0.06±0.01, Co 0.11±0.01, N=22.

Classification: ordinary chondrite (L3)

Specimens: About 100 g sample and 1 polished thin section are deposited in the Institution of Meteorites and Planetary Materials Research of GUT. The main mass is held by Bing-an Miao.