Bronze alloy production during the Iron Age of Luristan: a multianalytical study on recently discovered bronze objects

Application of bronze alloy to produce artistic and religious artefacts was commonplace during the Iron Age in western Iran (1500-550 BC). These bronze artefacts are the so-called Luristan bronzes and have been found often from excavated graves and sanctuaries. The aim of this paper is to study on alloy composition and manufacturing process in some recently excavated objects from the Iron Age cemetery of Baba Jilan, northern Luristan. For this purpose, some objects were analysed by quantitative ICP-MS as well as microscopic studies by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and metallography methods. Also, some comparisons were carried out between Baba Jilan and other analysed bronze objects from Luristan in order to identify the metalworking process in bronze objects from the Iron Age of western Iran. The results showed that all Baba Jilan samples are made of binary copper-tin alloy. Tin content was variable in the composition of the samples. The variety of tin constituents proved that alloying has been performed by an uncontrolled process to produce bronze. The microscopic studies also showed that the manufacturing operations are similar in the Luristan bronzes. It was carried out to identify probable similarities in the bronze alloy production in the Iron Age of the Luristan region.