Swayyah 002        26.707°N, 8.936°W

Saguia el Hamra, Western Sahara

Purchased: 2019 Feb

Classification: Martian meteorite (Shergottite)

History: Multiple stones (the largest weighing 3092 g) were found in early 2019. The majority of this material was purchased in February 2019 by Darryl Pitt from a Mauritanian dealer. One stone (100.34 g) was also purchased by Eric Twelker in February 2019 and two stones (total 98 g) were purchased by Ben Hoefnagels from Aziz Habibi in May 2019.Finally a stone (92.6 g) was acquired in October 2019 by Luc Labenne from a dealer in Zagora, Morocco

Physical characteristics: The stones lack fusion crust but in parts exhibit a desert weathering patina coating. Interiors have a mottled greenish-gray appearance.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Diabasic texture (mean grainsize 0.7 mm). Composed mainly of zoned clinopyroxene and maskelynite with accessory Cr-Ti-bearing magnetite, ilmenite, chlorapatite, pyrrhotite and rare baddeleyite. Grains of Fe-Ti oxides and clinopyroxene exhibit minor orange staining, and there are some thin veinlets of secondary calcite. Sparse glassy shock melt pockets are present.

Geochemistry: Subcalcic augite (Fs_21.4-22.1Wo_35.4-33.6, FeO/MnO = 26-28, N = 3), pigeonite (Fs_30.8Wo_13.1, FeO/MnO = 28), ferroan pigeonite (Fs_50.8-63.3Wo_17.2-12.8, FeO/MnO = 35-38, N = 4), maskelynite (An_57.8Or_1.0). Bulk composition (A. Falster, MMGM): analyses by X-ray fluorescence spectrometry on cut surfaces of three specimens gave (in wt.%): SiO₂ 48.56, TiO₂ 1.15, Al₂O₃ 12.00, Cr₂O₃ 0.11, FeO 15.68, MnO 0.45, MgO 6.47, CaO 12.84, K₂O 0.03, P₂O₅ 1.18.

Classification: Shergottite (diabasic).

Specimens: 31.9 g including two polished thin sections at UWB; remainder with DPitt, E. Twelker and B. Hoefnagels.