Northwest Africa 10172 (NWA 10172)

(Northwest Africa)

Purchased: 2015

Classification: Lunar meteorite (feldspathic breccia)

History: Purchased by Ali and Mohammed Hmani in April 2015, reportedly from Mauritania.

Physical characteristics: Several identically appearing pieces, 320, 328, and 140 g in several smaller pieces. Irregular exterior. A saw cut reveals a breccia with numerous fragmental feldspathic clasts set in a dark-gray groundmass.

Petrography: (C. Agee, UNM) This meteorite is mixture of a fine-grained cataclastic domains, large fragmental plagioclase and pyroxene crystals, smaller olivine fragments, symplectites, and shock melt veins. Accessory Fe-metal, silica, ilmenite, and chromite were observed.

Geochemistry: (C. Agee and N. Muttik, UNM) olivine Fa_36.8±5.3, Fe/Mn=98±5, n=7; pigeonite Fs_39.2±12.0Wo_13.9±5.1, Fe/Mn=61±5, n=10; augite Fs_35.8±16.2Wo_36.0±5.1, Fe/Mn=66±9, n=4; plagioclase An_93.3±3.7Ab_6.1±3.4Or_0.5±0.5, n=9; Shock melt (10 μm defocused electron beam, proxy for bulk meteorite composition): SiO₂=45.0±1.5, TiO₂=0.34±0.14, Al₂O₃=24.9±6.0, Cr₂O₃=0.17±0.12, MgO=7.8±3.9, FeO=7.7±4.1, MnO=0.11±0.06, CaO=14.2±2.5, NiO=0.01±0.02, Na₂O=0.43±0.14, K₂O=0.10±0.02 (all wt%), Fe/Mn=75±17, Mg#=64±5, MgO+FeO=15.6±7.8 (wt%), n=23.

Classification: Lunar (feldspathic breccia)

Specimens: 20.6 g including a probe mount on deposit at UNM; Ali and Mohammed Hmani hold the main mass.