Price : 1400 € |
Northwest Africa 15658 (NWA 15658)
(Northwest Africa)
Purchased: October, 2022
Classification: HED achondrite (Eucrite, melt breccia)
History: The meteorite was purchased from a meteorite dealer in Morocco.
Physical characteristics: Dark grayish rock with some fusion crust.
Petrography: Eucrite-melt breccia composed of up to 3 cm sized basaltic clasts and up to 500 µm sized mineral fragments in black shock melted matrix. Main minerals are exsolved pyroxenes and calcic plagioclase. The shock melt is mostly finely recrystallized and partly displays flow textures. Mineral grains entrained in the melt matrix often show resorption textures. Minor phases include silica, chromite, ilmenite, and FeS. No metallic iron detected.
Geochemistry: low-Ca pyroxene: Fs62.5±0.6Wo2.6±0.8 (Fs61.3-63.6Wo1.9-4.6, FeO/MnO=27-30, n=10); high-Ca pyroxene: Fs27.6±0.7Wo43.6±0.7 (Fs26.3-28.7Wo42.2-44.9, FeO/MnO=27-32, n=10); calcic plagioclase: An87.1±1.0 (An85.4-88.9, n=10).