Northwest Africa 10617 (NWA 10617)

(Northwest Africa)

Purchased: 2014

Classification: Rumuruti chondrite (R3)

History: Matthew Martin purchased a 294 g meteorite from a Moroccan dealer at the 2014 Tucson Gem and Mineral Show.

Physical characteristics: Exterior of the stone is shiny and wind polished. Sawn surfaces show a breccia of orange-tan clasts to 1 cm and rarer black clasts in an orange-tan matrix. Chondrules prominent to 2.5 mm, though majority <0.9 mm.

Petrography: A polished microprobe section chosen from the dominant orange-tan area. Abundant chondrules and fragments set in an orange-tan matrix. Chondrules to 1 mm. Dominant minerals are olivine, sub-calcic augite, and augite with minor low-Ca pyroxene, chromite, and FeNi-sulfide. One small (40 μm) Ni-rich Fe grain found. Sulfides heavily oxidized.

Geochemistry: (L. Garvie, ASU) Olivine, Fa_36.6±10.5 (Fa_16.9-59.9, n=15, Fe/Mn=94.8±22.9, NiO to 0.9 wt%, Cr₂O₃ to 0.4 wt%, and P₂O₅ to 0.5 wt%). High-Ca pyroxene, Fs_11.5±2.8Wo_42.1±5.4 (n=5). Low-Ca pyroxene, Fs_8.4Wo_0.5 (n=1).

Classification: Rumuruti chondrite (R3), weathering high.

Specimens: 24.5 g and one polished mount at ASU.