Northwest Africa 11263 (NWA 11263)
Morocco
Purchased: Feb 2016
Classification: Rumuruti chondrite (R3)
History: Purchased by Giorgio Tomelleri from a Moroccan dealer.
Physical characteristics: Several small fragments with black fusion crusts (total weight 281 g).
Petrography: (V. Moggi Cecchi, G. Pratesi, S. Caporali, UniFi): The thin section displays a texture consisting of separated, well-formed chondrules (ranging in diameter 0.3-0.9 mm), sometimes rimmed with pentlandite. Chondrules types are mainly PO, PP and POP; a forsterite-rich PO chondrule is present as well as an enstatite PP chondrule; the matrix is fine and contains olivine, orthopyroxene, clinopyroxene. Among opaque phases the most abundant is pentlandite although Ti-bearing chromite can be occasionally found.
Geochemistry: (V. Moggi Cecchi, G. Pratesi, S. Caporali, UniFi): Olivine in POP chondrules (Fa26.8±15.6, N = 15), orthopyroxene (Fs13.3±6.3Wo1.2±0.2, N = 8), clinopyroxene (Fs10.8±0.2Wo44.9±0.8, N = 4). Oxygen isotopes: (I.Franchi, R.Greenwood, OU) ?17O = 5.24 ?, ?18O = 5.99 ?, ?17O = 2.12 ?.
Classification: R3 chondrite
Specimens: 20 g including one polished thin section at MSN-Fi; main mass with Tomelleri.