NWA 13400 (CL3.9 !) – 0.03g


1 in stock


New class of carbonaceous chondrites !   CL 3.9 (currently C3 ungrouped but will be changed). 0.03g part slice. Sold in a collection box with label / certificate of authenticity.

Northwest Africa 13400 (NWA 13400)

(Northwest Africa)

Find: 2016

Revised classification and description.

Physical characteristics: Carbonaceous chondrite with high chondrule abundance (76 vol%) and low amounts of fine-grained matrix (17 vol%). Composed of irregularly formed Type-I chondrules, few Type-II chondrules, refractory inclusions (CAIs, AOAs), inter-chondrule metal and sulfide grains and matrix. Contains high amounts of (partly terrestrially oxidized) metal (magnetic susceptibility log χ (× 10-9 m3/kg) = 4.78). Fragments of chondrules and refractory inclusions occur, but macroscopically this sample is unbrecciated. It is of shock stage C-S2 and has a weathering grade of W2/3.

Geochemistry: Bulk Ti and Cr isotopic composition: ε50Ti ± 2σ = 2.60±0.07; ε54Cr ± 2σ = 0.70±0.13.

Classification: Due to its characteristically low amount of matrix, highly depleted concentrations of volatile elements, high magnetic susceptibility, low Fa values of nearly equilibrated olivine, and unique position in the ε50Ti-ε54Cr diagram, this sample was reclassified as a CL3.9 chondrite by Metzler et al. (2021).