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NWA 2373 Northwest Africa Purchased 2004 August Martian (basaltic shergottite) Small stones having a total weight of 18.1 g were purchased in Erfoud Morocco. Yellow brown with desert ablation/varnish surface only, no fusion crust. Description and classification (T. Bunch and J. Wittke, NAU): olivine phenocrysts (<1.25 mm in longest dimension) set in a fine-grained groundmass (<0.1 mm) of pigeonite, maskelynite, chromite, Ti-magnetite, augite, chlorapatite and sulfide. Olivine has cores of Fa30.7 FeO/MnO =51.9 and rims of Fa50.3, FeO/MnO = 53.3 and contains micron to submicron inclusions of chromite, glass, and barite. In thin section, one large olivine grain, which may be a xenocryst, is different from the rest with a core of Fa29.1, FeO/MnO = 43 and more tiny inclusions. A wide (0.2 to 0.4 mm), inclusion-free mantle on this grain is Fa32.3, FeO/MnO = 39.2. Pigeonite is zoned from Fs29.4Wo8.4 to Fs36.4 Wo14.1, FeO/MnO = 28; augite is Fs21.8 Wo29.1. Maskelynite is slightly zoned with a compositional average of An52.1Or2.1. Chromite, cr# = 87, fe# = 90.4. Overall texture, mineral content, and mineral compositions strongly suggest that this stone is paired with NWA 1068. Specimens: type specimen, and one thin section, NAU; main mass, Birdsell.
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