Agaraktem, Gao, Mali
Find: May 2009
TKW: 2,290 g
Half individual: 463 g
Very fresh diogentite endcut with polished cut surface and smooth black crust preserved in patches. Chromite crytals extending from crust. Obviously paired with Olivine diogenite NWA 5480.
Writeup from MB 101:
History: Four meteorites were discovered by an anonymous finder east of Agaraktem, Mali, in May 2009.
Physical characteristics: Four almost complete individuals totaling 2290 g.
Petrography: (R. Bartoschewitz, Bart) Polycrystalline olivine clusters (~50 vol%) of idiomorphic to hypidiomorphic cystals (<1 mm, average about 0.1 mm) distributed in schlieren-like bands within a matrix of xenolithic to hypidiomorphic pyroxene grains (about 1 mm), with rare intergranular feldspar. Chromite and metal occurs dominantly within pyroxene and olivine grains.
Geochemistry: (R. Bartoschewitz, Bart; P. Appel, B. Mader, Kiel) Pyroxene Fs23.8-25.4Wo2.0-4.4, olivine Fa29.3-30.3, feldspar An76-83Ab1-5. Chromite Al2O3 = 14.4-15.4, TiO2 = 0.9-1.1, MgO = 4.1-4.8; Kamacite Ni = 0.3-1.1, Co = 0.7-0.9 (all in wt%).
Classification: Olivine diogenite, S1, very fresh