Barbianello: An ungrouped nickel-rich iron meteorite found in Italy

Abstract

An unusual iron was found in 1960 in Barbianello (northern Italy, Pavia municipality) by a farmer, Clemente Allini, ploughing his fields. Years later, the iron was recognized as a meteorite but not officially classified. Our investigations indicate that Barbianello is a unique nickel-rich ataxite with dark and light regions texturally similar to, but compositionally distinct from, Santa Catharina iron. The light regions are chemically homogeneous, have a Ni content of 27.1 wt%, and a composition similar to irons of group IAB-IIICD. The dark regions are inhomogeneous with Ni ranging from 40 to 58 wt% and oxygen up to 20 wt%. Relics of unoxidized metal and textural relationships indicate that, unlike Santa Catharina, the dark regions result from the oxidation of a metal compositionally distinct from that of light regions.