NWA 13230 Ueilite 183g end piece, very rare classification – Ureilite melt rock!

Northwest Africa 13230 (NWA 13230)

(Northwest Africa)

Purchased: 2019

Classification: Ureilite

History: The meteorite was purchased from a meteorite dealer in Erfoud, Morocco.

Physical characteristics: Brownish rock without fusion crust.

Petrography: The meteorite shows a cumulate texture of about 1 mm sized equigranular sized olivine grains displaying typical reduced rims. Pyroxene appears to be recrystallized from a melt and shows patchy compositional zoning. Some melt regions contain abundant vesicles. Olivine and pyroxene are enriched in Cr₂O₃ and the meteorite contains graphite; calcite filled cracks attest to intense terrestrial weathering.

Geochemistry: olivine: Fa_18.6±0.1 (Fa_18.4-18.7, n=11), contains 0.52±0.07 wt% Cr₂O₃ and 0.37±0.02 wt% CaO; reduced rims in olivine: Fa_4.2-8.6; pyroxene: Fs_11.6±2.7Wo_11.0±6.7 (Fs_6.9-16.0Wo_4.1-24.8 ,n=14), contains 0.91±0.09 wt% Cr₂O₃ and 0.44±0.25 wt% Al₂O₃

Classification: Ureilite melt rock. The melt rock designation is from the recrystallized texture of pyroxene, with patchy compositional zoning, and the abundant vesicles (similar to NWA 10870).