The polishing of jade was already practiced in China three millennia before the Liangzhu culture. Its hardness and durability made it the preferred material for liturgical objects. At the time of Liangzhu, two shapes were very abundant, bi and cong, probably used together in funerary rituals.
The bi is a flat disc with a central hole. The cong is a complex tubular form whose outer wall is a square appearing over the cylinder on all or part of the height.
Each corner of the cong is used to position on both sides an archaic mask of taotie, similar as 1,000 years later on the Shang and Zhou bronze vessels but with a simpler style which brings in the best cases a good readability of the face.
The proportions of the Liangzhu cong have a high variety that has not been explained. A 24 cm high narrow tube with its square section divided into nine registers was sold for HK $ 8.5M including premium by Christie's on November 29, 2017.
On May 29, 2018, Bonhams sold for HK $ 21.7M including premium a Liangzhu cong 8.4 cm wide with two registers. The lower illustrations, centered on the rather flattened ridges, undeniably represent faces, each one with both concentric eyes, the nose and the mouth. On the upper register the image is stylized up to abstraction, as an ultimate figure of the creature to which the mysterious liturgy is addressed.
On April 2 in Hong Kong, Sotheby's sells a cong made around the mid Liangzhu period 4,500 years ago, lot 3020 estimated HK $ 8M. This piece 10 cm wide with flattened corners has the proportions of a bracelet but certainly did not have such a use.
Its extremely thin carving is very well preserved on half of the surface. The very detailed eyes that widen in the direction of the temples are not human.
SOLD for HK$ 9.6M including premium