Bi Disk

Nephrite is the proper name for the most common type of Chinese jade. It is a hard stone with a complex crystalline structure that makes it extremely difficult to carve. In fact, nephrite is so hard and tough that it cannot be cut or shaped with metal tools, and requires painstaking abrasion with mineral pastes or slurries made of harder stone, such as quartz, garnet, or diamond, in conjunction with various saws, drills, discs, and gouges.

Some of the earliest jade objects were made for religious rituals during the Neolithic Period, as early as 5000 BC. One such early ritual jade form was a disc called a bì, a shape that persisted in Chinese culture for thousands of years. Their original meaning and function has been lost; later tradition associated them with honoring the heavens. Bì were also placed in graves. In later times in China it was believed that jade helped preserve corpses from decay, and it is possible this belief prevailed in ancient times as well.

The surfaces of this bì are decorated with a pattern of raised dots that may represent simplified images of seeds or raindrops, a common motif in bì made from the 5th to the 1st centuries BC. The careful abrasion of the jade's surface that produced this pattern would have required many hours of work, thus making this bì a potent symbol of the owner's power and affluence along with any ritual significance it may have had.