NWA 12589 Brecciated LL7

Northwest Africa 12589 (NWA 12589)

(Northwest Africa)

Purchased: 2018 Oct

Classification: Ordinary chondrite (LL7)

Petrography: (K. Metzler, IfP) Brecciated ordinary chondrite with chondritic lithic clasts up to 7 mm. Clasts are recrystallized and contain chondrule relicts. Many secondary feldspar grains with sizes of 100 µm and larger. Rare (oxidized) metal with a maximum size of 1 mm.

Geochemistry: Mineral compositions and geochemistry: (K. Metzler, IfP) The mean olivine composition is Fa31.1±0.3 (30.2-31.5; n=14). The mean low-Ca pyroxene composition is Fs25.2±0.3 Wo2.9±0.5 (Fs24.5-25.6 Wo2.1-3.8; n=17).

Classification: LL chondrite based on mineral chemistry. Petrologic type 7 based on the equilibrated state of olivine and pyroxene, the large grain size of secondary plagioclase, and the high CaO concentration in low-Ca pyroxene.