Systematic radiocarbon dating from AMS indicates that a well-ordered mint was developed in the years 640-550 BC, and that Guan Zhuang is the world’s oldest known and securely dated mint site. Important new data for exploring the origin of monetization in ancient China.
The proposed minting dates are based on ceramic evidence only and are uncertain by radiocarbon dating, given technical limitations on excavations and ambiguity in the chronology of Chink period ceramics.
The absolute end of the coinage’s start date at these two locations is still uncertain, moreover, the lack of direct evidence of minting at these locations hinders a deep and correct understanding of the social and economic processes underlying the origin of the single currency in China, according to the Cambridge University website. .
The researchers discovered the ancient Mint site for casting coins with their standard names in Guan Zhuang in Xingyang, Henan Province, China, where the remains of various stages of the minting process were recovered from safe archaeological sites, and the Mint was part of a bronze foundry. Well organized and integrated under the auspices of the state of the Cheng, orderly radiocarbon dating now allows us to determine the emergence of standardized coins in China dating back to 640 – 550 BC.
The city of Guan Zhuang was founded in 800 BC, and was a regional center of the state of Zheng. Very many of the strategic river ports for crossing the Yellow River, as there are no known copper resources in the vicinity of the city.
Excavations between 2015 and 2019 revealed a large artisanal production area in the center of the outer enclosure of the city, which included workshops in the manufacture of bronze, ceramics, jade and bone-based industry, and the bronze foundry occupied the largest area. Its main features also include more than 2,000 production waste pits, most of which are between 1.50 and 3 m in diameter, and 1 to 2.5 m in depth. Besides ceramic fragments, these pits contained abundant remains related to bronze casting activities, including crucibles, ladles, bronze drips, unfinished or broken bronze artifacts, clay briquettes, charcoal, and kiln fragments.
A large building complex has not been disclosed at the foundry site. We can thus conclude that the actual workplaces for the production of bronze were simple huts, where various kinds of bronze artifacts were produced, including high-status ritual vessels, weapons, chariot fixtures, musical instruments, ornaments and tools.
The foundry produced coins with their final names and pottery molds, and, as is customary on the oldest coins, there are no inscriptions indicating the name of the area in which the coin was minted or its face value. The inner clay core is still incorporated into the socket of the handle, and a coin from the Eastern Han Dynasty (c. AD 200) has been recognized, with only the clay core and handle remaining.
Compositional analysis of the coins shows that they contain copper (Copper, 62.25 percent), lead (Lead, 24.3 percent) and tin (Tin, 8.97 percent). Notably, the average copper content of coins is 66.23-73.38 percent, with a lead content between 12.45 and 21.33 percent, and no evidence of any devaluation of the coin is shown by mixing a larger than normal proportion of lead.
The existence of minting activity in Guan Zhuang is documented by the numerous discoveries of clay cores and outer molds for casting coins. “.
Only one part was recovered from an external mold at the site, corresponding to a one-foot-tip bore, 22 mm long and 0.80 mm thick, this mold can only be used for a coin, because the bore is too shallow for any other known type of bronze tool. Moreover, a shallow groove along the edge of the die cavity indicates that the cast product will have a raised edge that is a distinctive feature of coins, and 54 clay cores have also been recovered for casting the hollow handle of coins.