Northwest Africa 16544 (NWA 16544) (Northwest Africa) Purchased: July, 2023 Classification: Mesosiderite History: The meteorite was purchased from a local meteorite dealer in Temara, Morocco. Physical characteristics: Two brownish fragments lacking fusion crust. Petrography: The meteorite is composed of silicate (about 65 vol%) and weakly altered metallic (about 35 vol%) portions. The silicate fraction predominantly consists of up to 2.5 mm sized zoned olivine, zoned low-Ca-pyroxene, exsolved low-Ca pyroxene, and calcic plagioclase. Olivine often contains low-Ca pyroxene-FeS symplectites. Minor phases include silica, chromite, ilmenite, FeS, and merrillite. In the metallic portion kamacite and taenite are present. Geochemistry: zoned pyroxene: Fs21.5±5.3Wo5.2±5.3 (Fs16.7-28.8Wo1.3-15.3, FeO/MnO=26-33, n=7); low-Ca pyroxene host crystals to augite exsolutions: Fs32.6±0.3Wo4.0±0.3 (Fs32.1-32.7Wo3.6-4.3, FeO/MnO=24-27, n=7); augite exsolutions: Fs15.5±0.5Wo40.8±1.3 (Fs15.0-16.4Wo38.1-41.9, FeO/MnO=18-22, n=7); olivine: Fa18.8±3.0 (Fa15.0-23.6, FeO/MnO=42±4, n=7); calcic plagioclase: An94.2±2.2 (An91.4-97.0, n=7)