Copper-based alloys in the Jezirah during the third millennium BC in light of archaeological evidence and laboratory analyses

This study demonstrates the development of alloying process and identifies the different alloys patterns used in Jezirah during the third millennium B.C. and examines if there was any relation between alloys patterns and the types of objects to be manufactured. To achieve these goals, findings of published studies that have analysed copper-based alloys chemically have been assembled and re-evaluated. In this multi-disciplinary paper, archaeometallurgical and archaeometric, 1279 copper-based alloys objects, from Jezirah, Mesopotamia and South-eastern Anatolian sites, were studied. Results of compositional analyses show that alloying process development in Jezirah during the third millennium B.C. was non-linear as was the case in the Mesopotamian and Anatolian schema. Three major types of different compositional patterns of copper-based alloys during the third millennium B.C. were used. At the beginning of third millennium B.C. arsenical copper alloys with arsenic content ≥ 4% were used alongside tin-bronze alloys with tin concentration from ≥ 2 to ≤ 5%. By the middle of the third millennium B.C., tin-bronze with tin content from ≥ 2 to ≥ 10%, arsenical copper alloys with arsenic content ≤ 2.5% and arsenical bronze with low tin and varied arsenic concentrations were diffused.