Sasanian and early Islamic copper-base metalworking at Qasr-e Abu Nasr, south-central Iran

A group of metal objects excavated at Qasr-e Abu Nasr in south-central Iran in the 1930s, now in the collection of the Metropolitan Museum of Art, has been analyzed to examine metalworking techniques and metallurgical processes. Thirty-three objects were studied and analyzed by micro-X-ray fluorescence, scanning electron microscopy-energy dispersive X-ray spectroscopy, and metallography techniques. The results of these analyses show a wide range of copper alloy compositions including impure copper, tin bronze, brass, leaded tin bronze, leaded brass and leaded ternary Cu-Sn-Zn (gunmetal) alloys. Also, two silver-copper and one pewter object were identified among the analyzed objects. The results of this interdisciplinary study provide new insights onto the archaeology of Qasr-e Abu Nasr, as well as present new information about the history and evolution of copper-base metallurgy on the Iranian Plateau during the Sasanian and early Islamic periods.