Lunar Meteorite

Northwest Africa 6831

northwestern Africa


from The Meteoritical Bulletin, No. 108


Northwest Africa 6831


(northwestern Africa)

Purchased: 2009

Mass: 20 g


Lunar Meteorite


History: The meteorite was purchased in 2009 from a local meteorite dealer in Erfoud, Morocco.


Physical characteristics: Dark greyish individual without fusion crust.


Petrography: (Ansgar Greshake, MNB) The meteorite is a relatively fine-grained fragmental breccia composed of up to 1 mm sized lithic and mineral clasts consolidated by a vesicular vitreous groundmass. Lithic clasts include basaltic and melt clasts; mineral clasts are dominantly calcic plagioclase, ferroan olivine, low-Ca pyroxene, pigeonite, and Ca-pyroxene. Minor phases include chromite, ilmenite, fayalite, and FeS.


Geochemistry: olivine: Fa40.7±5.5 (Fa31.7-50.4, n=25, FeO/MnO=82-102); low-Ca pyroxene: Fs23.7±0.2Wo3.5±0.3 (Fs23.5-24.0Wo3.2-4.0, n=5, FeO/MnO=55-66); pigeonite: Fs29.3±1.3Wo11.7±2.1 (Fs27.1-31.7Wo8.3-14.8, n=9, FeO/MnO=47-61); Ca-pyroxene: Fs60.7±3.6Wo24.5±2.0 (Fs54.6-67.3Wo20.1-26.9, n=9, FeO/MnO=66-75); calcic plagioclase: An92.6±1.3 (An90.1-93.8, n=20).


Classification: lunar (feldspathic breccia)


Specimens: Stefan Ralew


Randy Says…

I have not studied this one. The plagioclase is more albitic that is typical for a feldspathic lunar meteorite.


More Information

Meteoritical Bulletin Database

NWA 6831




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Prepared by: Randy L. Korotev

Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don’t contact me about the meteorite you think that
you’ve found until you read this and this.



Last revised: 30 May 2019