Northwest Africa 8753 (NWA 8753)

(Northwest Africa)

Purchased: 2014 Sep

Classification: Lunar meteorite (feldspathic breccia)

History: Purchased by Darryl Pitt in September 2014 from a dealer in Laayoune, Morocco.

Physical characteristics: Single stone (1345 g) consisting of white and dark gray clasts in a medium gray matrix.

Petrography: (A. Irving and S. Kuehner, UWS) Fragmental breccia composed of angular mineral clasts (anorthite, olivine, orthopyroxene, augite, exsolved pigeonite, chromite, troilite, kamacite) and sparse glass fragments (with composition equivalent to low-Ca pyroxene + anorthite) in a finer grained matrix. Rare grains of forsteritic olivine are present and are associated with Cr-pleonaste spinel.

Geochemistry: Olivine (Fa_17.9; Fa_35.6; Fa_9.8-10.7; FeO/MnO = 89-146; N = 5), orthopyroxene (Fs_26.9-44.0Wo_3.1-3.6, FeO/MnO = 65-79, N = 3), augite (Fs_17.5-17.9Wo_44.7-41.7, FeO/MnO = 43-53, N = 2), plagioclase (An_95.0-97.4Or_0.2-0.1, N = 3). Bulk composition (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 3.0, Na₂O 0.36; (in ppm) Sc 4.9, La 1.7, Sm 0.8, Eu 0.79, Yb 0.6, Lu 0.15, Th 0.3.

Classification: Lunar (feldspathic fragmental breccia). This specimen is notably felsic in comparison to other lunar feldspathic breccias, and contains accessory forsteritic olivine associated with Cr-pleonaste..

Specimens: 20.4 g including one polished thin section and a polished endcut at UWB; the remainder is held by DPitt.