Northwest Africa 13878 (NWA 13878)

Morocco

Purchased: 2021

Classification: Ureilite

History: (C. Muñecas, Expometeoritos) Samples were found by a nomad in a place in northwest Africa of unknown coordinates. These meteorites were eventually purchased by Carlos Muñecas in Errachidia.

Physical characteristics: The sample has a roughly tetragonal shape. The exterior of sample is coated in an orangish brown wind ablated fusion crust that wraps around the back in some places. The broken face shows the is crystalline.

Petrography: Description and classification (A. Love, App) Sample shows protogranular texture dominated by 1370µm (avg. L.D., n=70) olivine with subordinate twinned pigeonite showing graphite and fine blebby Fe metal at reduced grain boundaries. Additional minerals are: sparse FeNi metal and rare sulfides.

Geochemistry: Olivine: cores Fa_19.7±0.7, Fe/Mn=40.3±2.8, Cr₂O₃=0.7±0.0; reduced rims Fa_14.6±2.7, Fe/Mn=28.2±5.8, Cr₂O₃=0.7±0.0 n=12; pigeonite Fs_16.4±0.1Wo_7.5±0.0, Fe/Mn=24.1±0.40, n=6.

Classification: (Ureilite) Mineral compositions and textures suggest sample is a ureilite.

Specimens: Carlos Muñecas (Expometeoritos) holds the 1324 g main mass. A polished thin section, an oriented individual and several small fragments weighing 23.09 g are on deposit at App.