Lunar Meteorite: Northwest Africa 12593

from The Meteoritical Bulletin, No. 108

Northwest Africa 12593 (NWA 12593)

Mali
Purchased: 2017
Mass: 332.8 g (1 piece)

Lunar (fragmental breccia)

History: A single weathered stone lacking fusion crust found in Mali by nomads. Purchased by Dustin Dickens in Nouakchott, Mauritania, in 2017 from an anonymous meteorite dealer.

Physical characteristics: Dark, sand-blasted exterior, with many irregular shaped fragments set in a fine-grained dark groundmass. No fusion crust.

Petrography: (T. S. Hayden, M. Anand, OU) The meteorite is clast-rich fragmental breccia containing numerous mineral fragments and lithic clasts embedded in a fine-grained, vesiculated (regolith) matrix. The lithic clast population consists of basaltic clasts, granulite clasts and crystalline impact-melt breccias of olivine norite compositions. Size range of the clasts is 0.56-2.56 mm, and the main minerals are pyroxene, feldspar, olivine, silica, chromite, ilmenite, zircon and Ca phosphates (merrillite and apatite).

Mineral composition and Geochemistry: (T. S. Hayden, M. Anand, OU) Feldspar (An_93.8±2.7, Ab_5.9±2.5, n=39), pigeonite (Fs_30.5±9.1Wo_13.1±3.4, FeO/MnO = 59.3±6.6, n=59), augite (Fs_23.1±6.1Wo_30.9±4.3, FeO/MnO = 54.2±4.4, n=18), olivine (Fa_38.2±11.7, FeO/MnO = 103.2±7.1, n= 40). O isotopes (measured at OU): Repetition 1: δ¹⁷O = 3.328‰, δ¹⁸O = 6.361‰, Δ¹⁷O=-0.005‰ (linearized using a slope of 0.5247 (of Miller, M. F. (2002) GCA 66(11)), Repetition 2: δ¹⁷O = 3.203‰, δ¹⁸O = 6.106‰, Δ¹⁷O=-0.004‰ (linearized using a slope of 0.5247. Mean: δ¹⁷O = 3.266 ± 0.088‰ (1-sigma), δ¹⁸O = 6.234 ± 0.180‰ (1-sigma), Δ¹⁷O=0.000±0.006‰ (1-sigma).

Classification: Lunar fragmental regolith breccia.

Specimens: Specimen: 24 g type specimen held at OU. Dustin Dickens holds the main mass.

Randy Says…

I have not studied Northwest Africa 12593.

More Information

Meteoritical Bulletin Database

NWA 12593