Assamakka 002        19°22.167’N, 5°33.717’E

Agadez, Niger

Find: 2018

Classification: Iron meteorite (IIIAB)

History: Found by Mohlach Ahbsan in 2018 in a dune field near Assamakka.

Physical characteristics: The approximately 25 × 15 × 10 cm mass is characterized by a dark brown surface, and several areas where the surface appears to parallel the crystallographic angles within the octahedral structure. Significant terrestrial alteration is evident.

Petrography: (C. Herd and P. Hill, UAb) Petrographic investigation of a 1.5 × 1.5 cm polished and etched surface reveals a well-developed Widmanstaetten pattern with kamacite bandwidth 0.9±0.1 mm (n=7). No inclusions were observed. The exterior has been heavily weathered.

Geochemistry: ICP-MS data, using sample of North Chile (Filomena) as standard (C. Herd, P. Hill, and S. DuFrane UAb): Ni = 6.3, Co = 0.42 (both wt%); Ir = 10.9, Ga = 15, Ge = 30, As = 3.2, Sb = 0.09, Ru = 11.5, Re = 1.02, Os = 9.0, W = 0.6, Pt = 13.9, Cu = 137 (all μg/g).

Classification: (C. Herd, UAb): IIIAB iron, medium octahedrite. May be a low-Ni member of the IIIAB group. Alternatively, the bulk composition may have been affected by terrestrial alteration.

Specimens: Type specimen consisting of a 9.36 g slice and a 86.4 g representative specimen at UAb. Main mass with MtMorgan.