Chemical and microstructural comparison of the export porcelain from five different kilns excavated from Nanhai I shipwreck

Nanhai I shipwreck, a fully loaded merchant ship of the Southern Song Dynasty, once heading for the Southeast Asia, represents the prosperous international ceramic trades during that time. Recent excavation provides us with the great opportunity to investigate the export porcelain on this ship. Black Porcelain and green porcelain of Cizao kiln, white porcelain of Dehua kiln, bluish white porcelain of Jingdezhen kiln, celadon of Longquan kiln, and white porcelain of Minqing Yi kiln were analyzed chemically and morphologically by polarizing microscopy, energy dispersive X-ray fluorescence spectroscopy and scanning electron microscopy with energy dispersive spectroscopy. The chemical and microstructural features of each kind of porcelain, evidently different from each other, are discussed in detail in this paper. Among them, the Dehua white porcelain and the Jingdezhen bluish white porcelain may represent the best manufacture techniques for their purest glazes and bodies. Also, anorthite crystals are common in the calcium glazes of the Longquan celadon and the Jingdezhen bluish white porcelain. The most interesting structure among the samples observed is the structure of crystals and Mg-Fe rich phase separation in the black glaze of Cizao porcelain, which is also different from other black glazes studied in previous research.