Mixed-alkali glazed ceramics in 1st-6th century China: Technological characteristics and origination

Between the 1st and 6th centuries CE, the mixed-alkali glazed ceramics, which differ from the common type of ceramics, emerged from the Lingnan region. These glazes used Na₂O and K₂O as the main fluxes, bearing chemically similarities to mixed-alkali glass. To investigate their technological characteristic and potential origins, this study analyses the chemical compositions and Sr-Nd isotopic signatures of mixed-alkali glazed and calcium-glazed ceramics exacavated from sites in the Lingnan region. The results indicate that the fluxes in the mixed-alkali glazes may have derived from efflorescent salts associated with latrines or manurial soils. Comparative analysis with published data on mixed-alkali glass from the other parts of the world suggests that while these glazes show similarities to European mixed-alkali glass, they are more likely to be independently innovated, meanwhile still retaining characteristics of traditional Chinese ceramics. This research provides new insights into early glaze technology in China and demonstrates the value of isotopic analysis in tracing ceramic production processes and exploring the relationship between glass and ceramics industry.