Archaeologists have long been preoccupied with understanding the origins of metal coinage and monetization.

Now, a team working in the Henan Province of China has discovered an early minting site at Guanzhuang, complete with Chinese spade coins and their clay molds.

Experts have dated the site to 2,600 years ago, making this the oldest known coin mint in the world.

An analysis of the finds revealed that the mint produced ‘spade coins’, named for the similarity to the gardening implement.

Spade coins are the oldest form of commodity money used during the Zhou dynasty of China, and were used by the Zheng and surrounding regions until they were abolished by the first emperor of China in 221 BC.

Dr Hao Zhao from Zhengzhou University said: “The Guanzhuang foundry started around 770 BC, but at first it mainly produced ritual vessels, weapons and tools. It is about 150 years later that the minting activities appeared in this foundry.”

CT image of coin SP-1, one of the Chinese spade coins discovered in Guanzhuang.

Radiocarbon dating indicates that the site started minting from 640-550 BC, representing one of the oldest examples of metal currency production in China. As such, this new site can shed new light on the chronology of money and how it developed.

“Making coins was one of the most revolutionary financial innovations in human history,” said Dr Zhao, noting that it allowed wealth to be easily traded, counted, and hoarded.

Previous research had proposed that coins were first issued by merchants, making it much easier to trade, transport, and count wealth.

However, the mint at Guanzhuang is located close to the edge of the outer city, near the gates to the administrative inner city.

This could indicate that the government was involved in the early history of currency, although the limited number of artefacts found at the site means the exact affiliation of the foundry cannot be confirmed yet. Find out more