Northwest Africa 7678 (NWA 7678)

Morocco

Purchased: 2012 Aug

Classification: Carbonaceous chondrite (CV3)

History: Purchased by Adam Bates from a meteorite dealer in Morocco, August 2012.

Physical characteristics: 182 matching individuals/fragments, main mass 581 g. Dark weathered exterior, saw-cut reveals many small chondrules less than 1 mm and a few up to 5 mm, scattered CAIs up to 1 cm, set in a dark gray groundmass.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a numerous AOA, BO, PO, POP, and PP chondrules, most in the size range 300-1000 μm, in very fine-grained matrix. Abundant troilite; nearly all iron metal is oxidized by weathering.

Geochemistry: (C. Agee and M. Spilde, UNM) Chondrule olivine range: Fa_0.7-63.1, n=31. Type I chondrules: olivine Fa _3.0±1.9, Fe/Mn=49±31, Cr₂O₃=0.14±0.09, n=26; low-Ca pyroxene Fs_2.0±1.6Wo_1.3±0.9, Fe/Mn=25±20, n=23. Type II chondrules: olivine Fa _40.3±26.4, Fe/Mn=133±53, Cr₂O₃=0.08±0.04, n=5. Fassaite Fs_5.1±0.6Wo_58.4±1.2, Al₂O₃=23.69±0.14 wt%, Na₂O=2.65±0.00 wt%, n=2.

Classification: Carbonaceous chondrite (CV3)

Specimens: 65 g including a probe mount on deposit at UNM, Adam Bates holds the main mass.