Northwest Africa 14129 (NWA 14129)

(Northwest Africa)

Purchased: 2021 May

Classification: HED achondrite (Diogenite, melt breccia)

History: The meteorite was purchased from a group of meteorites hunters in Nouadhibou, Mauritania, in May, 2021.

Physical characteristics: Dark-brownish fragment without fusion crust.

Petrography: Melt breccia predominantly consisting of up to 300 µm sized, weakly zoned orthopyroxene, about 20-µm sized zoned olivine, and rare up to 100-µm sized calcic plagioclase crystals set in a matrix dominated by acicular pyroxene grains showing igneous zoning with orthopyroxene cores and pigeonitic rims. Several diogenitic pyroxenes served as nucleation sites and are overgrown by orthopyroxene and pigeonite. Minor phases are chromite and FeS. No metallic iron has been found. Eucritic material is absent in the section studied. The meteorite is strongly weathered and contains abundant calcite filled cavities and barite.

Geochemistry: Orthopyroxene pyroxene: Fs_28.6±1.4Wo_2.4±0.1 (Fs_25.5-29.8Wo_2.3-2.7, FeO/MnO=28-32, n=15); acicular matrix pyroxene: Fs_27.5±10.6Wo_6.0±4.8 (Fs_14.6-38.3Wo_1.4-14.9, FeO/MnO=24-31, n=7); olivine: Fa_31.5±4.0 (Fa_24.3-39.3, FeO/MnO=46±2, n=12); calcic plagioclase: An_92.4±0.5 (An_91.6-93.0, n=4)