Northwest Africa 4932

Algeria

Find: October 2007

Achondrite (lunar, feldspathic breccia)

History: Purchased by Greg Hupé from a Moroccan dealer in Tagounite, Morocco, in October 2007.

Physical characteristics: A single, light colored 93.3 g stone. The interior is light gray, mostly very fine grained with a few white clasts (Fig. 2), and prominent but sparsely distributed metal grains (surrounded by hydroxide staining).

Petrography: (A. Irving and S. Kuehner, UWS) Breccia composed of small gabbroic to troctolitic clasts (granular aggregates of rounded olivine grains and calcic plagioclase enclosed within low-Ca pyroxene with accessory Ti-chromite and troilite), sparse large grains of kamacite (up to 1 mm, partly altered to iron hydroxide) and rare large grains of silica polymorph in a dominant, very fine grained matrix of the same phases. There are secondary (terrestrial) veinlets and small patches of calcite.

Geochemistry: Low-Ca pyroxene (Fs_22.3–22.8Wo_5.9–5.3, FeO/ MnO = 51.9–53.0; Fs_20.8–36.1Wo_7.4–12.0, FeO/MnO = 56.5– 58.3), olivine (Fa_27.2–36.9, FeO/MnO = 87.7–96.3), plagioclase (An_94.9–96.4Or_0.3–0.1). Bulk composition (R. Korotev, WUSL): FeO 8.5 wt%, Sc 19.2 ppm, Sm 1.1 ppm, Th 0.6 ppm, Ni 450 ppm. section are on deposit at UWS. The main mass is held by Mr. G. Hupé.