Dhofar 312

Oman

Found 2001 January 11

Primitive achondrite (acapulcoite)

A 354 g stone without fusion crust was found in the desert. Mineralogy and classification (D. Badjukov and C. Lorenz, Vernad; F. Brandstätter, NHMV): consists mostly of euhedral silicate grains (0.05–0.4 mm) with interstices filled by Ni-containing iron oxides; approximate mineral modes (vol%) are low-Ca pyroxene = 35, olivine = 25, plagioclase = 15, augite = 5, opaques = 5 (chromite and rare inclusions of troilite and metal in silicates), terrestrial weathering products = 15, accessory chlorapatite; olivine, Fa_8.6±_0.5; ortho­pyroxene, Fs_7.6±_0.4Wo_1.8±_0.2; augite Fs_3.4±_0.5Wo_40.2±₂, containing 1.5 wt% Cr₂O₃; plagioclase, An_15.8±_1.4Ab_81.5±_2.7Or_2.6±_0.3; many pyroxene and olivine grains contain rounded inclusions (1–20 µm) of troilite, kamacite (6 wt% Ni), and rare taenite (26 wt% Ni); low shock stage; weathering grade, W3. Dhofar 312 may be paired with Dhofar 125. Specimens: type specimen, 70 g and thin section, Vernad; main mass with anonymous finder.