Lunar Meteorite: Northwest Africa 12831

The 9 stones of Northwest Africa 12831 (151 g). Photo credit: Alexandre Debienne
The largest stone of NWA 12831 (52.36 g). Photo credit: Alexandre Debienne
Two sides of a 15.4-g stone of NWA 12831. Photo credit: Alexandre Debienne
A 5.7-g endcut of NWA 12831. Photo credit: Alexandre Debienne

from The Meteoritical Bulletin, No. 108

Northwest Africa 12831 (NWA 12831)

Purchase: 2019 May
Mass: 150.8 g (9 pieces)

Lunar Meteorite (feldspathic breccia)

History: Purportedly found in Niger by nomads and purchased by Alexandre Debienne in May 2019 from a dealer in Agadir, Morocco.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed of mineral clasts of high-Ca pyroxene (some exsolved), low-Ca pyroxene (some exsolved), anorthite and sparse olivine in a finer grained matrix containing silica polymorph, Cr- ilmenite, Ti-chromite, fayalite, hedenbergite, baddeleyite, troilite and merrillite.

Geochemistry: Olivine (Fa19.3-46.7, FeO/MnO = 85-93, N = 4), low-Ca pyroxene (Fs17.2Wo3.3; Fs26.2Wo4.7; FeO/MnO = 50-58; N = 2), pigeonite (Fs31.9Wo13.4, FeO/MnO = 56), augite (Fs14.4Wo36.4, FeO/MnO = 44; Fs5.9Wo47.2; FeO/MnO =34; N = 2), pigeonite exsolution lamella (Fs52.4Wo6.9, FeO/MnO = 68), augite exsolution lamella (Fs24.8Wo42.2, FeO/MnO = 61), anorthite (An96.9-97.0Or0.1, N = 2).

Classification: Lunar (feldspathic breccia)

Specimens: 20.02 g including a polished endcut at UWB; remainder with Mr. A. Debienne.

Randy Says…

I have not studied Northwest Africa 12831. It is the 1st lunar meteorite reported to have come from Niger.

More Information

Meteoritical Bulletin Database

NWA 12831