Northwest Africa 2724
Achondrite (eucrite, polymict)
History: A 3804 g crusted complete stone was purchased in Erfoud, Morocco, in 2004.
Petrography: (J. Wittke and T. Bunch, NAU) The specimen mostly consists of cumulate basalt clasts that range from coarse-grained (~2 mm) to very fine-grained (~0.1 mm) with less than 5 vol% of subophitic basalts observed. Cumulate basaltic clasts are unusually low in ilmenite, chromite, and metal compared with other cumulate eucrites.
Composition: Despite the large range in grain size, pyroxene compositions show a rather narrow range: low-Ca pyroxenes (Fs59.1–62Wo3.2–3.8), pigeonite (Fs46.5–51Wo12.4–16.6), Ca-rich pyroxenes (Fs40–2.1Wo30.5–40.5), plagioclase (An89.4–92.7).
Classification: Achondrite (eucrite, polymict); low shock, minimal weathering.
Specimens: A 34 g type specimen is on deposit at NAU. E. Thompson holds the main mass.