Carved with yellow tone Hetian jade, this bi is decorated crop sprouts on both sides. The edge of the bi has sharp angle with multi-level planes which is quite different from single level plane. This fact may reflect the advancement of harder tools and more skillful technique of the Han Dynasty. Antiquity evidences include diffusive marking and differential weathering.Some researches believe that the ritual jade bi relates to the celestial body such as the black hole (image of lower left is one scene of the black hole published in internet.).