Description
Northwest Africa 11331 (NWA 11331)
(Northwest Africa)
Purchased: 2017 Apr
Classification: Lunar meteorite (feldspathic breccia)
History: Material excavated from a site near Tindouf, Algeria was purchased by Pierre-Marie Pelé in April 2017 from a dealer in Rissani, Morocco.
Physical characteristics: The stones (total weight 318 g) have distinctive reddish-brown, clay-rich exterior coatings. Fresh interiors exhibit whitish clasts in a dark-gray matrix.
Petrography: (A. Irving and S. Kuehner, UWS) Breccia composed of angular mineral clasts of olivine, anorthite, exsolved pigeonite, orthopyroxene, unexsolved pigeonite, augite, chromite and ilmenite, plus sparse glass fragments, in a finer grained partly vesicular matrix.
Geochemistry: Olivine (Fa20.1-53.8, FeO/MnO = 94-109, N = 3), orthopyroxene (Fs30.6Wo3.4, FeO/MnO = 54), low-Ca pyroxene host in exsolved pigeonite (Fs41.6Wo5.5, FeO/MnO = 57), pigeonite (Fs25.4Wo9.8, FeO/MnO = 54), augite (Fs10.0Wo42.9, FeO/MnO = 40), plagioclase (An96.4-96.7Or0.2, N = 2).
Classification: Lunar (feldspathic regolith breccia).
Specimens: 20.07 g in the form of a polished endcut at PSF; remainder with P. Pelé.
