NWA 12858 Rumuruti R3

Northwest Africa 12858 (NWA 12858)

(Northwest Africa)

Purchased: 2019 May

Classification: Rumuruti chondrite (R3)

Petrography: (K. Metzler, IfP) Unequilibrated chondrite, consisting of well-preserved chondrules and chondrule fragments set in a fine-grained matrix which is dominated by equilibrated olivine.

Geochemistry: Mineral compositions and geochemistry: Mean olivine composition Fa19.6±8.9 (Fa4.7-36.6); n=22. Mean low-Ca pyroxene composition Fs5.9±2.8 Wo0.8±0.5 (Fs1.8-11.8 Wo0.3-2.3); n=19. Mean olivine composition in fine-grained matrix (not included in olivine statistics) Fa47.5±0.8 (Fa46.7-49.0); n=7. Accessories are troilite and pentlandite; no metal was found.

Classification: R chondrite based on mineral chemistry. Petrologic type 3 based on unequilibrated olivine and pyroxene.