Northwest Africa 10923 (NWA 10923)

(Northwest Africa)

Purchased: 2016

Classification: Carbonaceous chondrite (C1/2, ungrouped)

History: The meteorite was bought in 2016 from Aziz Habibi, Morocco.

Physical characteristics: The small black individual is partly covered by fusion crust.

Petrography: The meteorite appears strongly brecciated and is composed of chondrule pseudomorphs (30-400 μm in diameter), hydrated mineral fragments, carbonates and Fe,Ni sulfides all sent into a fine-grained Fe-rich matrix. Some chondrules are surrounded by dust rims. In the section studied, no anhydrous silicates, e.g., olivine or pyroxene have been found. Also, no metal has been detected. Very low totals of defocused matrix analyses attest to high porosity and the presence of hydrous phases, i.e., phyllosilicates.

Geochemistry: Mean values of defocused matrix analyses (all wt%; N=50): SiO₂: 24.8, TiO₂: 0.13; Na₂O: 0.1; K₂O: 0.03, Cr₂O₃: 0.47, MgO: 16.7, MnO: 0.15, CaO: 0.62, FeO: 22.6, Al₂O₃: 2.44, NiO: 1.8, P₂O₅: 0.26, S: 2.24, Total: 72.14; Ca-carbonates contain about 2 wt% FeO.

Classification: Due to the lack of anhydrous silicates but preserved chondrule pseudomorphs, a C1/2 classification is suggested.