Essential "nwa 13102" - Mesosiderite 9.74g Slice Collection [WCu94B85]

"NWA 13102" - Mesosiderite 9.74g Endcut

Northwest Africa 13102 (NWA 13102)

(Northwest Africa)

Purchased: 2019 Aug

Classification: Mesosiderite

History: Purchased from a dealer in Zagora, Morocco in August 2019 by Juan Avilés Poblador on behalf of UAlic.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Recrystallized breccia composed of a variety of mineral clasts, some of which are rimmed by apparent reaction assemblages. Predominant component minerals are orthopyroxene (of several distinct compositions, with rare augite inclusions), olivine (of several distinct compositions) and anorthite, together with accessory kamacite (with taenite rims), silica (as acicular grains associated with anorthite), merrillite, chromite and troilite. Some orthopyroxene grains are rimmed by more ferroan orthopyroxene and some olivine grains are rimmed by orthopyroxene.

Geochemistry: Orthopyroxene cores (Fs17.6Wo0.9; Fs25.2Wo2.4; Fs33.7Wo2.3; FeO/MnO = 27-29, N = 3), orthopyroxene rims (Fs31.8-37.5Wo2.6-3.5, FeO/MnO = 25-26, N = 3), pigeonite rim on large orthopyroxene grain (Fs33.4Wo9.4, FeO/MnO = 26), olivine (Fa16.6-16.8; Fa34.4; FeO/MnO = 40-45, N = 3), orthopyroxene rim on magnesian olivine (Fs21.9Wo1.9, FeO/MnO = 25), augite inclusion in orthopyroxene (Fs16.9Wo42.0, FeO/MnO = 21), anorthite (An90.4-95.8Or0.3-0.1, N = 3).

Classification: Mesosiderite.

Specimens: 21.2 g including one polished endcut at UWB; remainder in the collection UAlic.