History: Found at 10:20 am on fine grained grano-diorite pediment. The flat, disk-shaped mass was stuck vertically in the ground, one third of the mass protruding from the soil.
Physical characteristics: A single, shield-shaped mass with brown and black colors. Cut face reveals a metallic unweathered interior.
Petrography: (J. Gattacceca, H. Pourkhorsandi, CEREGE): The etched section shows a polycristalline kamacite aggregate with crystal size to 550 μm. Abundant euhedral schreibersite 10-20 μm in size.
Geochemistry: (M. D’Orazio, DST-PI): Composition of the metal (ICP-MS) is Co=0.455, Ni=5.54 (both in wt%), Cr=76, Cu=125, Ga=67, Ge=191, As=4.4, Mo=6.2, Ru=25.8, Rh=2.72, Pd=1.67, W=3.33, Re=1.94, Ir=22.6, Pt=29.0, Au=0.39 (all in ppm).
This is a disk shaped iron with intriguing weathering pattern. Chemical erosion has reduced the initial surface and produced a set of protruding spikes up to 10 mm long.
B-473
January 19, 2018
Finds, Irons