Isheyevo

Bashkortostan, Russia.

Found 2003, October

Carbonaceous chondrite (Bencubbin-like meteorite)

One stone, weighing 16 kg, was found by a tractor driver in a field during harvest carrying in the Ishimbai region of Bashkortostan, close to the Isheyevo village. A small piece of the meteorite was issued to the Vernadsky Institute by Kazakov D.A., and Polozkov A.G, September 2004. Mineralogy and classification (Ivanova M.A. Vernad., Ulianov A.A. MSUM). Fusion crust is well developed, dark brown. The meteorite consists of FeNi metal grains, C, POP, rare BO chondrules (0.02-1 mm in size), chondrule fragments, CAIs, and matrix lumps. FeNi metal comprises from 50 to 70 vol%, and contains 4.2-8.4 wt% Ni, 0.2-0.5 wt% Co, and 0.03-0.6 wt% Cr; Co/Ni ratio is approximately solar. C chondrules don’t contain any FeNi metal grains, they are Mg-rich, and consist of pyroxene-rich cryptocrystalline material. Olivine, Fa_2.5, rare FeO-rich olivines, Fa_10-38 ; pyroxene, Fs_2.1Wo_1.7 , FeO-rich pyroxene, Fs_8-12Wo_0.8-1.8; troilite is Cr-rich, 2.5 wt% Cr. INAA data for a 20 mg chip: 2.74 wt.% Ni; 717 ppm Co; 2608 ppm Cr, 8.2 ppm Sc, and 1.59 ppm Ir. Petrological type 3; shock stage, S1; weathering grade, W1. Specimens: a type specimen, 24.3 g, and two sections, Vernad; main mass with anonymous finder.