Northwest Africa 18216 (NWA 18216) Mauritania Purchased: 2025 Classification: Mesosiderite History: The material was purchased in Nouadhibou, Mauritania, in 2025 by Mohamed Ali Loud from a meteorite dealer. Physical characteristics: Several dark brownish rocks lacking fusion crust. Petrography: The meteorite displays a dark brownish interior and is composed of silicate (about 65 vol%) and metallic (about 35 vol%) portions. The silica fraction predominantly consists of up to 5 mm sized low-Ca-pyroxene and calcic plagioclase. Many pyroxenes contain blebby and lamellar augite exsolutions. Metal is partly altered and mostly kamacite with less abundant taenite. Minor phases include silica, troilite, chromite, and merrillite. Geochemistry: low-Ca pyroxene: Fs33.5±0.2Wo3.3±0.3 (Fs33.1-33.9Wo2.7-3.6, FeO/MnO=22-25, n=7); Ca-pyroxene exsolutions: Fs15.7±0.7Wo41.9±1.3 (Fs15.1-16.9Wo39.8-43.0, FeO/MnO=19-21, n=7); calcic plagioclase: An91.3±1.2 (An90.1-93.2, n=7) Shock stage: low Weathering grade: moderate Classifier: A. Greshake, MNB This lot comes with certificate of authenticity. Thanks for your interest.