Seeing is believing: The colour of silver alloys and the global silver circulation in the Chinese Ming and Qing dynasties

This research investigates the correlation between colour perception and the circulation of silver in China during the Ming (1368–1644 CE) and Qing (1644–1911 CE) dynasties. The primary aim is to deepen our understanding of how silver alloys were perceived and experienced in this historical context while also situating our study within the broader context of the global silver trade. During the Ming and Qing dynasties, silver possessed immense historical significance as a precious commodity. We argue that copper had a more substantial influence on the final colour of silver alloys compared to lead. Furthermore, employing a colourimetric model, our Monte-Carlo simulation demonstrates that over 70% of silver from Mesoamerica to China could be discerned by nonexperts using only their unaided vision, largely due to the elevated copper content. Crucially, our simulation experiment reveals differing effects of copper and lead on the colour of silver alloys. The latter demonstrates minimal change until reaching a threshold of 15%, signifying that lead is a suitable and cost-effective substitute for silver. These findings suggest that the detection of silver purity was less demanding than previously assumed, opening up opportunities for arbitrage.