Choum 001        21.30°N, 12.96°W

Adrar, Mauritania

Find: 2021 Mar 28

Classification: Lunar meteorite (anorth)

History: This stone was found by Mohamed Biba Abdalahi on March 28, 2021, near Choum, Adrar, Mauritania. In September 2021, the main mass was exported by Rock & Co Society to its owner, Pascal Maugein, member of the French Astronomical Society, who provided the type specimen for classification.

Physical characteristics: A single gray, irregular stone. Cut surface show a gray interior with small vesicles and darker clasts up to cm.

Petrography: (J. Gattacceca, CEREGE) Igneous rock composed primarily of calcic plagioclase (about 90 vol%) and olivine. The texture, with the feldspathic groundmass containing skeletal olivine to 100 µm, and abundant vesicles with typical size 50 µm and up to 200 µm, indicate that the meteorite is a melt rock. The darker clasts observable on the cut surface are also melt rock. Rare troilite to 10 µm. Metal, chromite and ilmenite were not observed.

Geochemistry: Plagioclase An_96.5±0.3Ab_3.3±0.3Or_0.1±0.0 (n=5). Olivine Fa_23.0±3.2, range Fa_19.8-27.6, FeO/MnO = 89.0±15.6.

Classification: Lunar ferroan anorthosite, melt breccia. Plagioclase content, and olivine and plagioclase composition place this meteorite in the ferroan anorthositic suite (FAS) defined by Warren (1993).

Specimens: Type specimen at CEREGE. Main mass with Pascal Maugein.