Northwest Africa 8586 (NWA 8586)
Lunar meteorite (feldspathic breccia)
History: Purportedly found in Mauritania and purchased by Darryl Pitt in February 2014 from a dealer in Nouadhibou, Mauritania.
Physical characteristics: Single stone (704.5 g) composed of light gray to beige clasts in a dark gray matrix.
Petrography: (A. Irving and S. Kuehner, UWS) Fragmental breccia consisting of angular clasts in a finer grained matrix. Minerals are olivine orthopyroxene, subcalcic augite, augite, diopside), anorthite, ilmenite, troilite, rare kamacite and taenite. Several small mare basalt clasts were observed.
Geochemistry: Olivine (Fa21.7-47.0, FeO/MnO = 80-85, N = 3), orthopyroxene (Fs32.3-47.7Wo2.9-2.7, FeO/MnO = 53-65), subcalcic augite (Fs45.3-51.6Wo25.6-21.4, FeO/MnO = 55-59), augite (Fs13.7-14.2Wo44.3-44.0, FeO/MnO = 36-39), diopside (Fs8.7Wo40.8, FeO/MnO = 38), plagioclase (An96.9-97.4Or0.1-0.2).
Bulk composition: (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 4.3, Na2O 0.39; (in ppm) Sc 8.5, Ni 66, La 2.7, Sm 1.18, Eu 0.81, Yb 1.10, Lu 0.156, Hf 0.94, Th 0.7.
Classification: Lunar (feldspathic fragmental breccia).
Specimens: 20.1 g including one polished thin section at UWB. The main mass is held by DPitt.
Compositionally, Northwest Africa 8586 is a typical feldspathic lunar meteorite.
Meteoritical Bulletin Database
Korotev R. L. and Irving A. J. (2021) Lunar meteorites from northern Africa. Meteoritics & Planetary Science, 206–240.