Cong was first used in the Neolith Period. Ancient Chinese believe that the sky envelops the square ground like a lid. The shape of Cong follows such opinion. Its outer edge is square and the inner edge is rounded. In the ancient ceremonies, Bi was used to offer sacrifice to the heaven while Cong to the earth. This Cong was found on the waist of the marquis. There are patterns of animal faces carved on it.