Lunar Meteorite: Northwest Africa 13859

Two sides of a 21-g slice of Northwest Africa 13859. Photo credits: Meteolovers
Two sides of a 20.8-g slice of NWA 13859: Photo credits: Sergey Vasilev
Two sides of a 16.5-g slice of NWA 13859: Photo credits: Sergey Vasilev
Two sides of a 7.35-g slice of NWA 13859. Photo credit: Pierre-Marie Pelé.

from The Meteoritical Bulletin, No. 110

Northwest Africa 13859 (NWA 13859)

northwestern Africa
Purchased: 2021 March
Mass: 2045 g (several pieces)

Classification: Lunar meteorite (feldspathic breccia)

History: The meteorite was purchased by Said Yousfi from a dealer in Temara, Morocco. The largest second largest 356 g fragment was subsequently acquired by Luca Cableri. One sample was analyzed by Ansgar Greshake at MNB and a second sample by Paul Carpenter at WUSL.

Physical characteristics: Several dark grayish fragments without fusion crust. The largest ones weighing 694 g, 356 g, 283 g, 283 g, and 99 g, respectively, without fusion crust.

Petrography: Feldspathic breccia composed of mineral clasts and sparse troctolitic lithic clasts set in fine grained, partly glassy matrix. Minerals are predominantly plagioclase and olivine suggesting presence of abundant troctolitic material throughout the meteorite; pyroxenes are rare. Accessory phases are: FeS, ilmenite, Ti-bearing chromite, and secondary barite and calcite.

Geochemistry:  (A. Greshake, MNB) zoned olivine: Fa20.8±6.4 (Fa14.6-30.9, FeO/MnO=83±8, n=13); homogeneous olivine: Fa17.7±0.1, FeO/MnO=84±10, n=4; plagioclase: An96.6±0.8 (An95.3-97.6, n=6); (P. Carpenter, WUSL) olivine: Fa19.3-57.4, FeO=82-106, n=8; low-Ca pyroxene: Fs38.2Wo2.1, FeO/MnO=64, n=1); pigeonite: Fs17.7-24.2Wo7.4-15.0, FeO/MnO=42-54, n=3; augite: Fs16.9Wo39.4, FeO/MnO=45, n=1; plagioclase: An94.4-96.6Ab3.4-5.5Or0.0-0.1, n=3.

Classification: Lunar (feldspathic breccia, troctolite-rich).

Specimens: 20.5 g and a polished thin section are at MNB; 1 g and a polished mount are at UWB; main mass with Said Yousfi.

Randy Says…

I have not studied NWA 13859. The clasts are larger and more rounded than in most feldspathic lunar meteorites.

More Information

Meteoritical Bulletin Database

NWA 13859