| Price : 460 € |
Northwest Africa 15894 (NWA 15894)
(Northwest Africa)
Purchased: January, 2023
Classification: HED achondrite (Howardite, melt breccia)
History: The meteorite was purchased from a meteorite dealer in Morocco.
Physical characteristics: Five completely crusted individuals.
Petrography: Polymict breccia composed of up to 5 cm sized bulk rock, basaltic and black impact melt clasts plus a variety of up to 2 mm sized mineral fragments set in a finely recrystallized shock melted matrix. Predominant mineral phases are exsolved pyroxene, diogenetic low-Ca pyroxene (about 20%), zoned low-Ca pyroxene, and calcic plagioclase. Mineral grains entrained in the melt rock matrix often show resorption textures. Minor phases include silica, chromite, ilmenite, troilite, and FeNi metal.
Geochemistry: low-Ca pyroxene host to exsolution lamellae: Fs54.6±0.6Wo3.3±0.6 (Fs53.1-55.0Wo2.9-4.8, FeO/MnO=29-30, n=7); Ca-pyroxene exsolution lamellae: Fs37.8±0.9Wo37.6±0.6 (Fs36.5-39.2Wo36.9-38.7, FeO/MnO=26-31, n=7); diogenetic pyroxene: Fs25.0±0.2Wo2.6±0.1 (Fs24.7-25.2Wo2.6-2.7, FeO/MnO=25-27, n=7); zoned pyroxene: Fs37.5±7.3Wo5.7±0.2 (Fs31.3-51.7Wo5.3-6.0, FeO/MnO=25-31, n=7); calcic plagioclase: An90.7±1.0 (An89.6-92.2, n=7).
