Microscopic study on characteristic decorative black and white porcelain produced in Shanxi province, Jin and Yuan dynasties (ad 1115–1368), China

Black and white porcelain plays a critical role in Chinese decorative porcelain history. It is famous for its decorative styles and techniques, which create a strong black and white color contrast in its appearance. In this study, representative black and white porcelains produced in Shanxi province were analyzed by X-ray fluorescence, Raman spectroscopy, and SEM-EDS. The results show that both Ca-rich (~5.33 wt%) and Ca-poor (~1.99 wt%) glazes were used leading to quite different microstructures. The pigment particles of Ca-rich glazes are characterized by small size (≤2 μm), wide distribution, and tightly wrapped by anorthite. In contrast, they are larger (≥2 μm) and tightly cumulated together in Ca-poor glazes. Hematite is the major crystal in pigment, double-substituted by Al and Ti. The Al/Fe ratios are similar, but Ti/Fe ratios are quite different: They do not exceed 0.03% in Ca-poor glazes, whereas they reach 0.12% in Ca-rich glazes, suggesting that the origin of the pigments must be different. Al-rich mineral such as kaolin was added to the pigment preparation in Ca-rich glazes. The color of the pattern is mainly influenced by the size, quantity, and concentration of brown Ti-doping hematite, as well as the thickness of the glaze layer and other crystals and Fe ions. The fired atmosphere of Ca-rich glaze type seems less oxidizing than for Ca-poor glaze type. Overall, the results confirm that black and white porcelain has a variety of production techniques, which is attributed to the craftsman adjusting the techniques according to the composition of raw materials.