Brass before bronze? Early copper-alloy metallurgy in China

An artifact of brass apparently predating the “Bronze Age” was unearthed at Jiangzhai site (China, Shaanxi Province, 4700-4000 BC). So that we might infer the probable metallurgical process for the production of this early brass, we performed simulation experiments that, in turn, involved two widely differing methodologies. For convenience we refer to their metallurgical routes as “melting” on the one hand, and “solid-state reduction” on the other. Clearly, either of these processes could have supplied the starting material for the subsequent development of metal production leading to a casting technology, which is a highly significant step in the technical progress of metallurgy, whether of copper, brass, bronze or arsenical bronze. The distribution of zinc and lead in the brass artifact of the fifth millennium BC and several brass specimens produced by simulation experiments were analyzed by μ-X-ray fluorescence at the Shanghai Synchrotron Radiation Facility (SSRF). The results suggest that the archaeological brass artifact utilized alloy produced by a solid-state reduction process. This result is consistent with an indigenous origin in China.