NWA 10617 R3 Meteorite - 40.7g Complete Stone
One of only 28 R3 Chondrites discovered to-date, to say this meteorite is rare is a given. This is a complete individual with one minor chip on an edge. Originally classified as a CO3 in 2014, it was reclassified as an R3 by L. Garvie at ASU in 2016 after Dr. Garvie examined the stone. Dr. Garvie completed re-classification, which was approved by NomCom in 2016.
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, Fa36.6±10.5 (Fa16.9-59.9, 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, Fs11.5±2.8Wo42.1±5.4 (n=5). Low-Ca pyroxene, Fs8.4Wo0.5 (n=1).