The transition of alkaline flux of ancient Chinese faience beads (1046–476 BC): a case study on the samples from Pingdingshan, Henan province

Eleven faience objects unearthed from cemeteries (1046–476 BC) of the Zhou Dynasty in Pingdingshan, Henan province, China, were characterized by scanning electron microscopy–energy dispersive X-ray spectrometry. The analysis results provided information on the chemical composition and microstructure of the faience objects, and conclusions were drawn regarding the forming and glazing methods, as well as the related glazing materials. Soda-rich, potash-rich, and mixed-alkali fluxes, as well as the cementation and efflorescence glazing methods, were utilized in forming these faience objects. Conventionally, a glazing mixture was applied to the quartz body, probably to strengthen it for handling prior to firing. In combination with the published data on other Chinese faience objects, it was possible to suggest the provenances, transition of the alkaline flux with time, and product and technology exchanges of the faience objects from Central China during the Zhou Dynasty (1046–221 BC). The soda-rich faience objects were imported from the West and were later replaced with the mixed-alkali faience ones since the middle Western Zhou Dynasty (976–878 BC). Since the early Western Zhou Dynasty (1046–977 BC), Chinese native potash-rich faience had been produced in the Zhou realm. This study will provide some insights into the technology exchange and origin of the potash-rich and mixed-alkali faience objects unearthed in China.