Copper alloying practices of Urartian metalwork: Results of pXRF analysis from Ayanis, Yukarı Anzaf, and Çavuştepe (Türkiye)

Copper alloy metalwork of the Iron Age Urartian kingdom (9th-7th centuries BCE) is famous for its high degree of sophistication and skill. This study presents the results of energy dispersive portable X-ray fluorescence spectrometry (ED-pXRF) analysis used to characterize 73 Urartian copper alloy objects, primarily from the fortresses of Ayanis, Yukarı Anzaf and Çavuştepe in eastern Türkiye. It includes material dating to the reign of three different Urartian kings between the 9th and 7th centuries BCE in order to assess and compare alloying strategies across object types, sites, and time periods. The results indicate that the majority of the objects are made of bronze alloy (Cu-Sn), but there are also a range of other alloys represented, including low-Zn alloys (Cu-Zn-Sn). Cu-Sn alloys appear to have been chosen for objects worked by hammering, such as shields, likely due to their hardness. Cast objects frequently included Pb or Zn in addition to Sn, likely to facilitate easier casting. Arrowheads are enriched in As and Sb, consistent with the use of a fahlore raw material source different from the other artifact classes. These correlations are present in objects from different sites and time periods, suggesting that alloying practices were shared between craftspeople throughout the kingdom.