At the Neolithic archaeological site at Liangzhu in China, located 16 kilometers northwest of Hangchou in Cheking province, many objects of stone, jade, and black pottery were discovered between 1936 and 1939. While the exact date of the Liangzhu culture is uncertain, it is considered to be between 3500 and 2000 BC. A characteristic feature of the Liangzhu-culture pottery is a thin black finish and a layered structure of the body consisting of a black core sharply changing to a gray or red band ending in the black surface.

The focus of this paper is to explain why the cores of the vessels are black and why the colored bands occur and what they indicate about the firing conditions of the pottery. Analyses were ca rried out using SEM, electron-beam microprobe, X-ray diffraction, photo-electron spectroscopy, and polarizing microscopy. From this evidence, it is clear thait a clay vessel containing abundant charcoal was thrown on the wheel and then fired under reducing conditions so that charcoal was retained and iron reduced. Just before completion of the firing or during the cooling phase, air was allowed to enter the kiln and a limited thickness of the outer core was oxidized. Then, for decorative purposes, the surface was heavily smoked, and/or a thin iron-containing slip layer was reduced in smoke and burnished.