[meteorite-list] Northwest Africa 2115

[nelson oakes]

Northwest Africa 2115
     Northwest Africa
     Purchased January 2004
     Achondrite (olivine diogenite)
A partly crushed stone of 642.3 g was purchased from a dealer in Erfoud, Morocco. Description and classification (T. Bunch and J. Wittke, NAU): Yellowish green to brown, friable olivine diogenite, Very large olivine phenocrysts (up to 18.5 mm in longest dimension) and orthopyroxene (up to 11 mm) remain in a highly crushed, grainy matrix; millimeter-sized chromite is also visible in the hand specimen. Unzoned olivine, Fa27.7; FeO/MgO = 45.4; orthopyroxene, Fs22.9Wo1.5; FeO/MnO = 26.9; chromite, cr# = 88.6; mg# = 18.4. Also contains minor metal (Ni = 0.29 wt %; Co = 0.59 wt %) and troilte. No plagioclase was observed. Modal analyses, based on 4 mm2, give 47 vol % olivine, 49 vol % orthopyroxene, 3 vol % chromite and <1 % troilite and metal. Shock level, S3, weathering grade, W2. Likely paired with NWA 1877, Specimens; type specimen, NAU; main mass, Oakes.
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