Lunar Meteorite: Northwest Africa 12909

from The Meteoritical Bulletin, No. 108

Northwest Africa 12909 (NWA 12909)

(Northwest Africa)
Purchase: 2019
Mass: 2742 g (1 piece)

Lunar meteorite (feldspathic breccia)

History: Purchased by Zuokai Ke in Chenzhou, China, in May 2019 from Moroccan meteorite dealer.

Physical characteristics: Single stone, desert weathered exterior, sawcuts reveal a fragmental breccia with many white, feldspathic clasts set in a dark-gray groundmass.

Petrography: (X. Gu, CSU-China; C. Agee, UNM) This meteorite is composed of anorthite (55%), olivine (23%), augite (15%), orthopyroxene (6%), with ubiquitous minor kamacite, troilite, ulvospinel, ilmenite, Cr-spinel, silica, schreibersite and pentlandite. Brecciated clasts sizes range from several micrometers to 1 mm.

Geochemistry: (X. Gu, CSU-China) Olivine Fa_30.4±12.5, n=26; low-Ca pyroxene Fs_22.1±10.3Wo_3.5±0.8, Fe/Mn=63±8, n=8); augite Fs_26.9±11.0Wo_22.6±14.1, n=17, plagioclase An_97.3±1.9Or_0.2±0.3Ab_2.6±1.9, n=11. (C. Agee, _UNM) Olivine Fa_30.0±10.9, Fe/Mn=88±8, n=6; pigeonite Fs_28.9±6.0Wo_13.2±5.8, Fe/Mn=53±9, n=3; augite Fs_20.0±14.9Wo_39.2±7.3, Fe/Mn=42±2, n=3, plagioclase An_96.3±0.6Or0.2±0.1Ab_3.5±0.6, n=3.

Classification: Lunar feldspathic breccia

Specimens: 23.2 g including a probe mount on deposit at UNM, Zuokai Ke holds the main mass.

Randy Says…

I have not studied Northwest Africa 12909. Modally, it appears to be a brecciated anorthositic troctolite, but one less forsteritic than the NWA 5744 clan.