Synergistic chemical and structural colorations in early polychromic ceramics - A case study of Tang Changsha glaze

The emergence of polychromic glazes during Tang period reflects intercultural communications than 1000 years ago. It also highlights a significant technological advance in ceramic history. However, the colouration mechanisms in high -fired Tang glazes are still not well understood. In this work, we unravel the mysteries of colourful Tang glazes through a case study of the Changsha kiln samples. Colorants in varied concentrations and oxidation states as well as microstructures resulted from phase separation and impurity are found responsible for the glaze appearances. More importantly, we highlight the mixing effects of different coloration ingredients that generate additional colours and hues. A direct observation of co -existence of reduced copper nanoparticles and liquidliquid phase separation in Tang Changsha glaze is achieved as well. These fresh results and analyses provide an insightful assessment of the diversity of Tang Changsha glazes and promote the perception of ancient ceramics in a more scientific manner.