Ramlat Fasad 523        19°07.054’N, 53°37.596’E

Zufar, Oman

Find: 08 Feb 2017

Classification: Ureilite

History: A single complete stone was found during a search for meteorites.

Physical characteristics: Dark brown, surficially porous stone, 7 cm maximum dimension. No fusion crust. External rind of 2-3 mm thickness flakes off due to weathering.

Petrography: (S. Rout, E. Gnos, B. Hofmann) The meteorite consists of roughly equal amounts of olivine and pigeonite and has a typical ureilitc texture. Olivine has reduced Fe-poor rims, 20-50 μm wide, with minute inclusions of Fe metal. Pyroxene grains show only minor reduction along rims. Silicate grain size is 0.7-1.5 mm. Shock stage of silicates is low (S1-2). Carbon is present as both coarsely crystalline graphite laths and associated coarse grains of diamond (up to 20 μm). Medium weathering (most iron metal oxidized, silicates are unaffected).

Geochemistry: (S. Rout, Bern): Olivine cores: Fa_15.1±0.4, Fe/Mn = 40±2, Cr₂O₃=0.63±0.05 wt% (N = 50), reduced rims: Fa_7.2±3.7 (N = 34). Pigeonite cores: Fs_13.6±0.1Wo_7.0±0.1, Cr₂O₃ 1.04±0.02 wt% (N = 19).

Classification: Based on texture, mineralogy and geochemistry this is a unbrecciated, monomict, ferroan/magnesian ureilite. Possibly paired with Ramlat Fasad 524 found at a distance of only 12 m.

Specimens: 32.47 g including one polished thin section at NMBE, main mass: MHTO