NWA 8455 Location unknown
Northwest Africa
Purchased: 2014
Classification: Lunar meteorite (feldspathic breccia)
History: Purchased from a Moroccan meteorite dealer in 2014.
Physical characteristics: Single stone, no fusion crust, irregular exterior with desert patina, freshly broken surface and saw cut reveals a few scattered millimeter-sized white feldspar clasts set in a very dark gray groundmass.
Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows this specimen to be a fragmental breccia composed of clasts (up to ~500 ?m) of individual plagioclase, pyroxene, olivine grains, and also lithic clasts (up to ~1 mm) of gabbro and shock melt, set in a pervasive matrix of micrometer- to submicrometer-sized silicates. Accessory ilmenite, silica polymorph, chromite, phosphate, Fe-metal.
Geochemistry: (C. Agee and N. Muttik). Olivine Fa26.6±3.5, Fe/Mn=100±9, n=28; pigeonite Fs26.2±6.2Wo8.7±4.4, Fe/Mn=58±5, n=22; augite Fs21.5±8.4Wo34.5±6.8, Fe/Mn=55±11, n=11; plagioclase An95.1±1.0Ab4.5±1.0Or0.4±0.1, n=4. Shock melt (proxy for bulk composition) SiO2=44.6±1.1, TiO2=0.59±0.53, Al2O3=26.1±3.2, Cr2O3=0.10±0.03, MgO=6.8±1.8, FeO=5.0±1.3, MnO=0.04±0.03, NiO=0.02±0.01, Na2O=0.69±0.20, K2O=0.19±0.04 (all wt%).
Later one more fragments were found that are absolutely identical to the previous one.
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