Lunar Meteorite: Northwest Africa 16256

from The Meteoritical Bulletin, No. 113

Northwest Africa 16256 (NWA 16256)

(Northwestern Africa)
Purchased: 2023 June
Mass: 2490 g (many pieces)

Lunar meteorite (gabbro)

History: Purchased by Adam Aaronson in June 2023 from a dealer in Gaoua, Mali. The main mass was subsequently acquired by Robert Ward.

Petrography: (A. Irving, UWS, and P. Carpenter, WUSL) The specimen is a very coarse grained gabbro (mean grainsize ~3 mm) composed of equant grains of relatively homogeneous, relatively ferroan subcalcic augite (some grains as large as 5 mm, pale tan in thin section) and maskelynite. Minor constituents include symplectitic intergrowths of fayalite+hedenbergite+silica polymorph, ilmenite, Cr-ulvöspinel, troilite, chlorapatite and zirconolite.

Geochemistry: Subcalcic augite (Fs_57.6-61.4Wo_22.8-23.1; Fs_35.3Wo_32.4; FeO/MnO = 52-63, N = 3), hedenbergite (Fs_54.3Wo_42.3, FeO/MnO = 55), fayalite (Fa_77.7-92.8, FeO/MnO = 66-89, N = 4), maskelynite (An_93.6-77.0Or_0.1-3.3, N = 20).

Classification: Lunar (unbrecciated gabbro). The plagioclase (now transformed to maskelynite) in this plutonic igneous specimen exhibits compositional zoning from anorthite to bytownite. The more sodic compositions are associated with later-formed symplectites and apatite.

Specimens: 25.7 g including one polished thin section and a polished mount at UWB; main mass (2419 g) held by Mr. R. Ward.

Randy Says…

I have not studied Northwest Africa 16256. As a coarse-grained lunar meteorite with basaltic mineralogy and a fusion crust, it may be launch-paired with Asuka 881757 (Antarctica) and MIL 05035 (Antarctica) as well as Ramlat Fasad 532/535 (Oman, but no fusion crust).

More Information

Meteoritical Bulletin Database

NWA 16526