Description
Northwest Africa 13844 (NWA 13844)
(Northwest Africa)
Purchased: 2020 Jan
Classification: Carbonaceous chondrite (CM2)
Petrography: (J. Gattacceca, CEREGE) Chondrules with average apparent diameter 390±320 µm (n=8) set in abundant iron-rich fine-grained matrix. Chondrules have distinct fine-grained dust rims with radial fractures. Accessory minerals: sulfides, rare metal (mostly enclosed in silicates). Calcium carbonates are present. Matrix low EMPA analytical totals indicate the presence of hydrous phases.
Geochemistry: Olivine Fa7.9±8.6, range Fa0.6-25.6 (n=6). Cr2O3 in ferroan olivine 0.53±0.16 wt%. Low-Ca pyroxene Fs3.6Wo0.9 (n=2). Defocused matrix analyses: FeO 22.3±0.4 wt%, analytical total 80.0±0.3 (n=3).
Classification: Carbonaceous chondrites (CM2)