The Chinese Cong

A cong (Chinese: 琮; pinyin: cóng; Wade–Giles: ts’ung2) is a form of ancient Chinese jade artifact. It is a straight tube with a circular bore and square outer section with more or less convex sides. The outer surface is divided vertically or horizontally such that the whole defines a hollow cylinder embedded in a partial rectangular block. Proportions vary: a cong may be squat or taller than it is wide. The outer faces are sometimes decorated with mask-like faces, which may be related to the taotie designs found on later bronze vessels.
Although it is generally considered to be a ritual object of some sort, the original function and meaning of the cong are unknown. Later writings speak of the cong as symbolizing the earth, while the bi represents the heavens. The square represents the earth and a circle represents the heavens.