Northwest Africa 10133 (NWA 10133)

(Northwest Africa)

Purchased: 2014 Apr

Classification: Lunar meteorite (feldspathic breccia)

History: Purchased in April 2014 by Sergey Vasiliev and Marc Jost from a dealer in Tan Tan, Morocco.

Physical characteristics: A group of many small beige to gray stones (total 54.2 g).

Petrography: (A. Irving and S. Kuehner, UWS) Following optical examination of all of the small stones constituting the type material, three representative stones were selected for detailed microprobe and bulk chemical analysis. Each specimen consists of small mineral clasts of anorthite, olivine, pigeonite, orthopyroxene, augite, subcalcic augite, forsterite, fayalite, silica polymorph, ilmenite, troilite, zircon (one grain >100 μm) and rare kamacite set within a fine grained vesicular matrix containing minor barite. Rare mare basalt lithic clasts are also present.

Geochemistry: Olivine (Fa_6.0, FeO/MnO = 71; Fa_22.7-29.9, FeO/MnO = 91-106, N = 2; Fa_84.3-89.4, FeO/MnO = 88-99, N = 2), pigeonite (Fs_24.6-31.9Wo_11.4-6.5, FeO/MnO = 56-72, N = 3), orthopyroxene (Fs_26.8-45.0Wo_4.4-3.8, FeO/MnO = 61-73, N = 2), subcalcic augite (Fs_22.0-48.5Wo_25.1-33.0, FeO/MnO = 62-66, N = 3), augite (Fs_13.1-38.5Wo_44.5-39.6, FeO/MnO = 49-60, N = 2), plagioclase (An_93.5-96.5Or_0.4-0.1, N = 4). Bulk composition (R. Korotev, WUSL): mean abundances for three separate stones determined by INAA of subsamples are as follows: #A (in wt.%) FeO 5.1, Na₂O 0.49; (in ppm) Sc 10.1, Cr 790, Ni 150, La 5.9, Sm 2.7 Eu 1.07, Yb 1.8, Lu 0.26, Hf 1.9, Th 0.9; #B (in wt.%) FeO 6.1, Na₂O 0.50; (in ppm) Sc 12.0, Cr 930, Ni 290, La 10.0, Sm 4.6, Eu 1.15, Yb 3.2, Lu 0.44 Hf 4.0, Th 1.6; #D (in wt.%) FeO 5.5, Na₂O 0.49; (in ppm) Sc 10.0, Cr 760, Ni 280, La 9.2, Sm 4.3, Eu 1.20, Yb 2.8, Lu 0.39, Hf 3.2, Th 1.4.

Classification: Lunar (feldspathic regolithic breccia). Despite the mineralogical and compositional heterogeneity among these small stones, we conclude that they are paired with Northwest Africa 8641, Northwest Africa 8682 and Northwest Africa 10077.

Specimens: 10.9 g including two polished pieces at UWB. The remaining material is held jointly by Mr. S. Vasiliev and Mr. M. Jost.