Lunar Meteorite: Northwest Africa 12279

NWA 8046-clan pair?

NWA 12279 alleged “pair” on ebay. April 2020: There are several ~5-g complete (uncut) stones identified as “a NWA 12279 probable pairing found in Algeria in 2016” being sold on eBay. I do not know why the seller suspects that the stones are probably paired. Also advertised for the stone in the photo above: “light oriented piece, with mini regmaglypts.” Given that there is no fusion crust, it cannot have regmaglypts or be “oriented.” Caveat emptor. What I think we are seeing here is differential weathering, where the feldspathic (light-colored) clasts have weathered preferentially to the dark, glassy matrix, leaving depressions.

from The Meteoritical Bulletin, No. 107

Northwest Africa 12279 (NWA 12279)

Tindouf, Algeria
Purchased: 2016 October 10
Mass: 1830 g (1 piece)

Lunar Meteorite (feldspathic breccia)

History: The meteorite was purchased in Denver USA by Zhouping Guo and Guobing Zhong on September, 2017 from Adam Aaronson.

Physical characteristics: A single bulk specimen, with sepia fresh fusion crust and low weathering degree. A large impact molten mass was observed in the specimen.

Petrography: This lunar meteorite comprises two petrographic areas: impact melt breccia and anorthosite. The anorthosite includes forsterite, pigeonite, low-Ca pyroxene, plagioclase and minor minerals such as ilmenite, chromite, quartz and other opaque minerals. It has a subophitic structure. The impact-melt breccia contains various types of lithic clasts (anorthosite, olivine-gabbro, gabbro), mineral and glassy fragments. The matrix consists of very fine-grained, cryptocrystalline (~0.1mm) and vitric particles with sporadic small vesicles.

Geochemistry: (J.K. Zhou, H.Y. Chen, Z.P. Xia, Guilin University of Technology, China): Olivine, Fa12.8-46.3Fo53.8-87.3, FeO/MnO=66.3-96.9 (n=29); Orthopyroxene, Fs15.5-32.2Wo2.98-4.22En64.9-80.3, Fe/Mn(mol)=54.5-69.3 (n=3); Pigeonite: Fs23.2-53.1Wo7.19-23.7En39.8-57.4, Fe/Mn(mol)=51.1-61.7 (n=6); Augite, Fs8.42-44.4Wo31.4-44.1En18.7-47.5, Fe/Mn(mol)=37.1-53.9 (n=14); Plagioclase: An92.9-98.5Or0.06-0.69 (n=15); Spinel: MgO, 20.1%-23.6%; Al2O3, 59.5%-69.2%; Cr2O3, 3.91%-6.00%; FeO,6.05%-7.46%.

Classification: Lunar (anorthositic impact-melt breccia)

Specimens: 30.2 g including one polished thin section are deposited in College of Earth Sciences, Guilin University of Technology, China; Remaining material with Guobing Zhong and Zhouping Guo.

Randy Says…

I have not studied Northwest Africa 12279. It might be another stone of the NWA 8046clan, considering the description and reported find location. I do not have a photo of the 1830-g NWA 12279 type specimen.

More Information

Meteoritical Bulletin Database

NWA 12279

Lunar Meteorites
List – ABC123 Order
List – Al2O3 Order