Using radiocarbon dating, Chinese archaeologists have confirmed that a bronzeware casting workshop at the ruins of Guanzhuang in Xingyang City, the western part of the provincial capital Zhengzhou, Henan, had begun to mint standardized metal money around 640-550 BC, making it the earliest known coin making workshop in the world.

 

During further excavation, four types of relics related to coin manufacturing were unearthed at the site, including finished coins, used and unused coin molds as well as outer molds, said Han Guohe, an archaeology professor from Zhengzhou University.

 

Archaeologists have also uncovered several pits where large quantities of bronzeware casting waste were dumped, with two finished metal coins found in one of the pits.

 

The coins are believed to be the currency in circulation back in Spring and Autumn Period (770-476 BC) and the Warring States Period (475-221 BC), one of ancient China's earliest metal coins, according to Gao Xiangping, the archaeological team leader of excavation at the Guanzhuang ruins.

 

New discoveries at the workshop site not only provide a clear archaeological background for studies on the exact time of currency production but also help reflect the social and economic mechanism during the development of metal money, Han added.

 

The Guanzhuang ruins, first excavated in 2010, is a complete city site built about 800 BC during the Western Zhou Dynasty and was abandoned about 450 BC. A large area of handicraft workshops was found at the site, where various handicraft activities including bronzeware casting, pottery making and bone artifact production had been carried out.

 

A paper on the coin workshop has been published by Antiquity, a peer-reviewed journal of world archaeology.