Price : 4200 € |
Northwest Africa 16164 (NWA 16164)
(Northwest Africa)
Purchased: 2023 Jun
Classification: HED achondrite (Eucrite, melt breccia)
History: The meteorite was purchased from a Morrocan meteorite dealer on the meteorite fair in Ensisheim, France.
Physical characteristics: Dark grayish fragment with some fusion crust.
Petrography: Eucrite-melt breccia composed of up to s cm sized basaltic clasts plus up to 700 µm sized mineral fragments in black melt rock matrix. Main minerals are exsolved pyroxenes and calcic plagioclase. The shock melt is mostly finely recrystallized and contains acicular pyroxene and plagioclase. 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 host to exsolution lamellae: Fs60.0±0.5Wo2.9±0.6 (Fs58.9-60.7Wo2.1-4.0, FeO/MnO=29-31, n=10); Ca-pyroxene exsolution lamellae: Fs26.9±0.3Wo42.9±0.3 (Fs26.2-27.2Wo42.2-43.3, FeO/MnO=29-33, n=10); calcic plagioclase: An87.2±0.6 (An85.9-88.2, n=10).