Analyzing the formation mechanism of ‘Huoshihong’ characteristics in the blue-and-white porcelain of the Yuan Dynasty from Jingdezhen

Energy Dispersive X-Ray Fluorescence, field emission scanning electron microscopy and X-ray Absorption Fine Structure analysis were used to study the formation mechanism of the ‘Huoshihong’ (火石红) on the blue-and-white porcelain body of the Yuan Dynasty. The color rendering component for ‘Huoshihong’ is mainly α-Fe2O3. Liquid phase forms in high temperatures due to the invasion of external flux is the primary condition of the formation of ‘Huoshihong’. Fe enrichment also occurs at the places, but the Fe2+/Fe3+ ratio where ‘Huoshihong’ occurs is similar to other areas. The formation of ‘Huoshihong’ can be divided into three stages: oxidation of the body and reduction of Fe2O3, blending of Fe2+ into the liquid phase and enriched on body surface, re-oxidation of Fe2+ and crystallization stage of nanometer-scale α-Fe2O3. Experimental archaeological results corroborate theoretical analysis showing that the appearance and re-oxidation of Fe2+ are necessary conditions for ‘Huoshihong’ formation.