Verkauf - for sale NWA 5289

New - NWA 5289 - the first IVA iron from North West Africa

Northwest Africa 5289
Northwest Africa
Find: 2007
Iron (IVA)

History: A single iron mass was purchased from a Moroccan dealer in August 2007 by M. Graul (Bernau, Germany).

Physical characteristics: The 296 g mass, measuring approximately 81 x 54 x 30 mm, has a flattened shape. The portion of the surface originally sitting into the soil is partially covered with caliche deposit, whereas the remaining portion appears to be polished by winddriven sand. No fusion crust is preserved.

Petrography (M. D’Orazio, DST-PI): Widmanstätten pattern with kamacite lamellae (bandwidth = 0.32 ± 0.04 mm) and plessite fields in approximately 1:1 volumetric ratio. The kamacite lamellae show abundant Neumann bands and occasionally are displaced along shear planes. Accessory phases: schreibersite, troilite, chromite (tiny euhedral crystals included in troilite) and anhydrous Fe-phosphate (up to 1.3 mm in maximum length and surrounded by swathing kamacite). Geochemistry: (M. D’Orazio, DST-PI) Composition of the metal (ICP-MS) is Co = 0.404, Ni = 9.02 (both in wt%), Cu = 111, Ga = 2.0, Ge < 1, As = 12.0, W = 0.36, Re = 0.08, Ir = 0.80, Pt = 3.76, Au = 2.33 (all in ppm) Classification: Iron meteorite (IVA), fine octahedrite. Type specimen: A 20.3 g etched endcut sample and 11.3 g of shavings are on deposit at DST-PI. M. Graul holds the main mass.

Meteoritical Bulletin Nr. 94/S.16 > Meteoritical Bulletin Nr. 94