Glazing Technology of Fujian Black Glaze of Song Dynasty

The Fujian black glaze of Song dynasty was investigated due to a controversial phenomenon of brown layer appearing under the black glaze. Microstructure and chemical compositions of the brown layer and the black glaze were characterized by SEM/EPMA. The results show that the content of iron oxide in the brown area was significantly higher than that in the black glaze area, and the solvent content was lower than that in the black glaze area. The surface of brown layer was covered by the hematite and magnetite crystallines, which resulted in the brown. Between the brown layer and black glaze region there was no obvious interface region, the thickness of brown layer was only one-fifth to one-tenth of that of the black glaze. The chemical compositions and microstructure of the brown areas and black glaze were significantly different, and there wasn’t obvious boundary between these two regions which could be caused by the ‘make-up soil’ in the matrix. Thus, the brown area was likely to be of secondary glazing fabricated using another formula, and the formula was different from the black glaze.