Entrèves        45°49.14’N, 06°54.82’E

Valle d’Aosta, Italy

Find: May 1987

Classification: Iron meteorite (IAB-MG)

History: A single 20 × 17 × 18 cm mass was found in 1987 by an anonymous bomb-slivers hunter near a moraine at the border of the Brenva glacier, on the Italian side of Mont Blanc, near Entrèves. The sample was subsequently sold to Claude Scavone, a French mineral collector who sold it to Giorgio Tomelleri, an Italian meteorite collector

Physical characteristics: The main mass, weighing 17.3 kg, displays several small fusion pits and is apparently well preserved from rust. A distinct coarse grained Widmanstaetten pattern is visible on sawn and etched surfaces.

Petrography: (V. Moggi Cecchi, G. Pratesi, S. Caporali, UniFi). The 2 × 2 cm cut and etched chip examined contains no silicates. Coarse-grained (~5 mm width) equigranular kamacite grains with 120° grain boundaries can be distinguished, with rare taenite. No Neumann lines are visible. Schreibersite is present as rare laths, up to 150 μm in width and to 1 mm in length, within some kamacite grains and at grain boundaries. Schreibersite is frequently surrounded by iron oxides.

Geochemistry: SEM-EDX spot analyses, all in wt% (V. Moggi Cecchi, G. Pratesi, S. Caporali, Uni-Fi): schreibersite P19.9±0.2Fe44.6±0.6Ni35.6±0.8 (N=6); taenite Fe70.5±0.5Ni29.5±0.2 (N=6); kamacite Fe92.6±0.6Ni7.4±0.2 (N=5). Bulk composition (C. Herd and G. Chen, UAb) Ni=69.0, Co=4.5 (both mg/g); Cu=124, Ga=91, As=11.2, W=1.8, Ir=3.9, Pt=9.9, Pd=3.4, Ru=7.4, Re=0.4, Os=5.2, (all µg/g). Obtained by ICP-MS using North Chile as standard.

Classification: IAB-MG, coarse octahedrite. Composition is consistent with IAB Complex, Main Group (MG). The composition of this meteorites is extremely similar to that of Campo del Cielo. However Neumann bands are absent whereas they are abundant in Campo del Cielo.

Specimens: A polished chip weighing 28 g is on deposit at MSN-FI. Main mass with Giorgio Tomelleri.