A tubular, jade object, circular on the inside and enclosed in a rectangular body, made in various sizes and used for ritual purposes in ancient China. Cong were described in ancient Chinese texts as symbols of rank and were used as ritual objects primarily in the Shang (18th-12th century BC) and Chou (1111-255 BC) dynasties. They have been found in graves, arranged with bi disks around the corpses of the elite. The cong is thought to have symbolized Earth or possibly to have been an astronomical instrument.