Classification: Eucrite melt breccia S-igh / W-low
Place/Time: 2022 in Mauritania
Mass: 29.4 kg
History: Two identical stones of 19200 g and 10200 g were purchased in June 2020 by Aziz Habibi from a Mauritanian dealer. The larger stone was subsequently acquired by Marcin Cimala.
Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Monomict breccia composed of angular eucrite clasts with intergranular texture in a fairly sparse melt rock matrix (dark gray in thin section) containing entrained crystalline debris. Minerals are exsolved pigeonite, calcic plagioclase, silica polymorph, chromite (some grains compositionally zoned), ilmenite, troilite and Ni-free Fe metal. Some thin dark shock veinlets crosscut clasts, and secondary calcite is present as veins and also infilling cavities in the matrix.
Geochemistry: Low-Ca pyroxene host (Fs58.7-60.7Wo2.3-4.4, FeO/MnO = 30-32, N = 4), augite exsolution lamellae (Fs25.7-26.8Wo42.6-43.6, FeO/MnO = 31-32, N = 4), plagioclase (An88.1-90.1Or0.5-0.3, N = 4).
Classification: Eucrite (monomict melt-matrix breccia).