Northwest Africa 2737 Find: 2000 Achondrite (Martian, chassignite) History: In August 2000, meteorite collectors discovered a stone fragmented into nine pieces (308 g, 128 g, 74 g, 47 g, 38 g, 6.4 g, 3.3 g, 2.0 g, and 4.3 g for a total mass of 611 g) in the western part of the Sahara. Petrography and Geochemistry: (P. Beck, Ph. Gillet, B. Reynard, B. van de Moortele, ENSL; J.A. Barrat, M. Bohn, I. Cotton, UBO) Olivine (Fo78.2–79.1; Mn/Fe = 0.018; ~89.6 vol%), chromite (4.6 vol%), low-Ca pyroxene (En78.5Wo2.7Fs18.8 to En76.6Wo3.2Fs20.2), high-Ca pyroxenes (En73.5Wo8.0Fs18.5 to En64.0Wo22.1Fs13.9; Mn/Fe 0.030 [total of low- and high-Ca pyroxene ~4.1 vol%]), and sanidine glass (~1.6 vol%) with traces of apatite. The texture is that of a cumulate dominated by mm-size anhedral to subhedral olivine crystals, sometimes poikilitically enclosed in augite (En54.6Wo32.8Fs12.6 to En46.7Wo44.1Fs9.2). Oxygen isotopes: (I. Franchi, R. Greenwood, OU) δ17O = 2.40, δ18O = 4.02, ∆17O = 0.315; δ17O = 2.30, δ18O = 3.85, ∆17O = 0.295 (all ‰, n = 2). Furthermore, NWA 2737 displays trace element abundances similar to Chassigny. For example, its REE pattern resembles that of Chassigny but with a more pronounced LREE enrichment. Classification: Achondrite (Martian, chassignite); highly shocked. Specimens: A 20 g type specimen is on deposit at ENSL. B. Fectay and C. Bidaut of La Mémoire de la Terre hold the main mass. Important information: This item is a micro, there is a 1 cm scale cube for reference. Provenance: Lyon-Colvin-Denoncin. This lot has no reserve price and comes with its certificate of authenticity. Thanks for your interest.