Lot 44. A dark green jade bi disc, Late Warring States period-Western Han dynasty. Diameter 6½ in., 16.5 cm. Estimate: 15,000 - 20,000 USD. Lot sold: 18,900 USD. © Sotheby's 2021

of circular form pierced with a central aperture, densely carved to both sides with spiral patterns enclosed within line borders, the stone a deep hunter-green streaked with russet and areas of calcification.