Lunar Meteorite: Northwest Africa 4932

Northwest Africa 4932 (top, 93 g) and an end cut (bottom). Photo credit: by Greg Hupé
Two sides of a slice of NWA 4932 (photo credit: by Greg Hupé)
Up close in the lab. NWA 4932 contains many small grains of iron-nickel metal. Photo credit: Randy Korotev

from The Meteoritical Bulletin, No. 94

Northwest Africa 4932 (NWA 4932)

Find: 2007 October
Mass: 93.3 g (1 piece)

Achondrite (lunar, feldspathic breccia)

History: Purchased by Greg Hupé from a Moroccan dealer in Tagounite, Morocco in October 2007.

Physical characteristics: A single, light colored 93.3 g stone. The interior is light gray, mostly very fine grained with a few white clasts (Fig. 2), and prominent but sparsely distributed metal grains (surrounded by hydroxide staining).

Petrography (A. Irving and S. Kuehner, UWS): Breccia composed of small gabbroic to troctolitic clasts (granular aggregates of rounded olivine grains and calcic plagioclase enclosed within low-Ca pyroxene with accessory Ti-chromite and troilite), sparse large grains of kamacite (up to 1 mm, partly altered to iron hydroxide) and rare large grains of silica polymorph in a dominant, very fine grained matrix of the same phases. There are secondary (terrestrial) veinlets and small patches of calcite.

Geochemistry: Low-Ca pyroxene (Fs22.3-22.8Wo5.9-5.3, FeO/MnO = 51.9-53.0; Fs20.8-36.1Wo7.4-12.0, FeO/MnO = 56.5-58.3), olivine (Fa27.2-36.9, FeO/MnO = 87.7-96.3), plagioclase (An94.9-96.4Or0.3-0.1).

Bulk composition: (R. Korotev, WUSL): FeO 8.5 wt.%, Sc 19.2 ppm, Sm 1.1 ppm, Th 0.6 ppm, Ni 450 ppm.

Classification: Achondrite (lunar, feldspathic breccia).

Specimens: A total of 18.7 g and one polished thin section are on deposit at UWS. The main mass is held by Mr. G. Hupé.

Randy Says…

NWA 4932 is a crystalline impact-melt breccia that is moderately mafic but low in KREEP elements. It is compositionally and texturally very similar to SaU 300, collected ~3400 km away. The two stones may have been blasted off the Moon by the same impact.


More Information

Meteoritical Bulletin Database

NWA 4932


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