CHINA Large cloudy white jade bi disc. Diameter: 59 cm. Approximate weight: 15 Kg. 20th century. The manufacture of discs dates back at least to the Liangzhu culture (3300 -2000 BC) and continued over several millennia, right up to the Han dynasty. But variants, more or less ornate, were produced much later. TheMusée national du Palais exhibits a Ming dynasty example, decorated with dragons on one side and round seeds on the other. The disc seems to have originally had a ritual function.