Northwest Africa 4448 (NWA 4448)

Morocco

Found: 2005

Classification: Primitive achondrite (lodranite)

History: A stone was recovered from the lower Algerian desert in 2005 and sold in Erfoud, Morocco, in 2006.

Physical characteristics: A partially crusted, 36.3 g stone with a freshly fractured surface.

Petrography: (T. Bunch and J. Wittke, NAU): granoblastic texture with a grain size of 0.05 to 1.7 mm, mean = 0.55 mm. The largest grains are orthopyroxene oikocrysts that enclose rounded olivine chadacrysts. Modal analyses (in vol. %): orthopyroxene, 49 (oikocrysts = 4); olivine, 42; metal, 6; sulfide, chromite, and phosphates, 3. Weathering grade and the shock level are low.

Geochemistry: Orthopyroxene, Fs_11.0Wo_2.2, FeO/MnO 16-18; orthopyroxene oikocrysts, Fs_10.6Wo_1.6; olivine, Fa_8.5, FeO/MnO = 19 to 23; sulfide Ni 2.36 wt %; metal Ni = 5.4 wt %; chromite cr# = 80; merrillite CaO = 47.5 wt % and P₂O₅ = 46.3 wt %; apatite CaO = 56.9 wt % and P₂O₅ = 42.4 wt %; Oxygen isotopes (D. Rumble, CIW): A cleaned and metal-free sample was analyzed by laser fluorination. Replicate analyses are, respectively, δ¹⁷O of 0.539 and 0.442‰; δ¹⁸O of 3.551 and 3.413‰; Δ¹⁷O of -1.329 and -1.3534‰.

Classification: Achondrite (lodranite).

Specimens: 6.3 g and one thin section are on deposit at NAU. The main mass is held by Mr. Aziz Habibi.