Tests on 36 Koryŏ Copper Coins: Copper Content Ranged From 60.95% to 92.57%, Alloy Mix Diverged From Song Dynasty Recipes
A study published in npj Heritage Science on November 13 used X-ray fluorescence spectrometry to characterize the metal composition of 36 Koryŏ Dynasty copper coins. The earliest native copper coins of the Korean Peninsula were first minted in the Koryŏ Dynasty, and morphologically and epigraphically they share notable similarities with contemporary Chinese Song Dynasty copper coins.
The results show that copper content fluctuates approximately from 60.95 wt.% to 92.57 wt.%, lead content from 0.11 wt.% to 24.45 wt.%, and tin content from 1.87 wt.% to 23.85 wt.%. The coins are bronze specimens consisting primarily of copper, lead and tin, yet their alloy ratios are highly variable and inconsistent from coin to coin.
When compared with Song Dynasty coin alloy recipes, the analyzed samples exhibit marked compositional divergence. The authors conclude that the pattern indicates distinctive alloying practices and an independent minting tradition for Koryŏ copper coinage, rather than a simple copy of Song recipes.
The paper is by Tingqing Li of the Department of History (Zhuhai) at Sun Yat-sen University and Haiping He of the College of Materials Science and Engineering at Beijing University of Chemical Technology. The coin samples were unearthed within the territory of the Democratic People's Republic of Korea and provided by collector Qu Ming; each specimen was authenticated by numismatic experts, and Dr. Chen Jiaqi assisted with the experiments.
The work was supported by the National Social Science Fund of China (grant No. 24BSS038) for a project on the ancient currency system of the Korean Peninsula from an East Asian perspective (918–1392), which also covered the experimental expenses.
The article was received on June 6, 2026, accepted on October 13, 2026, and published on November 13, 2026, with the digital object identifier 10.1038/s40494-026-03092-4. It is being shared early as a citable version that will be replaced by the final version of record.
Source: npj Heritage Science
Published by GSM · USA (original Chinese edition)
Photo: 图：高丽王朝时期的铜钱。来源：Gary Todd from Xinzheng, China, CC0，维基共享资源。 / Photo: Copper coins of the Goryeo Dynasty. Credit: Gary Todd from Xinzheng, China, CC0, via Wikimedia Commons.
