Northwest Africa 10252 (NWA 10252)

(Northwest Africa)

Purchased: April 2015

Classification: Pallasite (Main group, anomalous)

History: Purchased by Darryl Pitt from Moroccan meteorite dealer in April 2015.

Physical characteristics: Irregular exterior, dark metallic patina, slight oxidation. Polished saw cuts show angular orange-brown-green, translucent olivines set in fresh, unoxidized metal.

Petrography: (C. Agee, UNM) Olivine is the only silicate phase present. Approximately 98% of the metal consists of very fine-grained (<1 μm) plessite, with kamacite occuring as a thin mantling around olivine crystals. Accessory schreibersite, chromite, Ni-rich sulfide, and Ca-Mg phosphates were observed.

Geochemistry: (C. Agee and N. Muttik, UNM Olivine Fa_13.3±0.1, Fe/Mn=47±3, n=10; plessite Fe=82.9±5.7, Ni=15.9±5.8, Co=0.60±0.08 (all wt%), n=10; kamacite Fe=94.4±1.0, Ni=5.9±0.9, Co=0.83±0.05 (all wt%), n=10; schreibersite Fe=59.3±2.6, Ni=25.3±2.6, Co=0.28±0.04, P=14.2±0.2 (all wt%), n=4. Oxygen isotopes (K. Ziegler, UNM) laser fluorination of acid-washed bulk subsamples gave (mean of 3), respectively, δ¹⁷O = 1.351, δ¹⁸O = 3.049, Δ¹⁷O = -0.258 permil (linearized).

Classification: Pallasite, main group anomalous based on oxygen isotopic composition, likely paired with NWA 10023.

Specimens: 22.6 g including a probe mount on deposit at UNM, DPitt holds the main mass.