| Price 300€ |
Fezzou 002 30.794°N, 4.861°W
Centre-South, Morocco
Find: 2023 Sep
Classification: Angrite
History: Found in September 2023 in eastern Morocco near the village of Lahfira at 30.794°N, 4.861°W and subsequently purchased from the finder by Mark Lyon.
Physical characteristics: A single broken stone in two pieces (11340 and 1028 g) with a thin coating of vesicular black fusion crust.
Petrography: (A. Irving, UWS, and P. Carpenter, WUSL) The specimen is an aggregate (mean grainsize ~350 µm) of interlocking anhedral grains exhibiting an allotriomorphic-granular texture. Composed predominantly of Al-Ti-augite (pink in thin section), Ca-bearing olivine, kirschsteinite and almost pure anorthite together with accessory hercynitic spinel (pleonaste), troilite and rare Fe metal. Blades or lamellae of kirschsteinite are present within some olivine grains. Some polycrystalline pyroxene-rich clusters and clusters of kirschsteinite+olivine up to ~3 mm in size are present. Vesicles are absent.
Geochemistry: Al-Ti-augite (Fs16.3-17.9Wo56.2-57.8, FeO/MnO = 77-101, Al2O3 10.1-11.4 wt.%, TiO2 1.5-2.8 wt.%, N = 5), olivine (Fa59.4-60.5Ln2.4-3.2, FeO/MnO = 61-68, N = 4), kirschsteinite (Fa37.7-39.3Ln45.0-48.1, FeO/MnO = 59-65, N = 4), anorthite (An99.9-100.0Or0.0, N = 4), pleonaste [Fe0.78Mg0.30Al1.88 Ti0.02Cr0.04O4]. Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively δ17O 2.217, 2.194, 2.137; δ18O 4.444, 4.350, 4.239; Δ17O -0.130, -0.103, -0.101 per mil (all data linearized, TFL slope = 0.528).
Classification: Angrite (allotriomorphic-granular).
