The glazed tiles in Yaogang village kiln in the Ming dynasty, Nanjing, China: Unveiling the unique mysteries of their techniques and compositions through comprehensive analysis methods

Abstract The kiln site in Yaogang village is the location of the imperial glazed kiln in Nanjing, China: the Jubaoshan glazed kiln. It mainly supplied the glazed tiles required for the construction of imperial buildings, such as the Ming Imperial Palace and Bao’ensi. A total of 15 samples of glazed tiles were selected and analysed by optical microscopy (OM), X‐ray diffraction (XRD), thermal decomposition (TD) and energy dispersive X‐ray fluorescence (EDXRF) spectroscopy to determine their apparent morphology, phase composition, firing temperature and chemical composition, respectively. Research indicates that the glaze and body of glazed tiles exhibit distinct characteristics, lacking an intermediate layer. The glaze layer is a vitreous phase with excellent meltability and no residual crystals, while the body primarily consists of a matrix, particulate matter and pores. The phase composition of the body mainly comprises quartz and mullite, with some samples also containing trace amounts of rutile, hematite and sanidine. The firing temperature for ceramic body samples of glazed tiles in Yaogang village reaches approximately 1000°C, indicating a relatively high level of firing. The raw materials used for the body differ from those employed in the Ming Imperial Palace and Bao’ensi and Dangtu; their source remains to be explored. The primary chemical components present in yellow and green glazes on glazed tiles in Yaogang village are PbO and SiO 2 , respectively. Different colouring elements contribute to various hues observed on glazed tiles: Fe plays a significant role in yellow glaze coloration, while Cu and Fe jointly influence green glaze coloration.