Northwest Africa 2115
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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.
