5905874 Cong, c.3000-2500 BC (jade) by Liangzhu culture (3400-2250 BC); width: 6.5 cm; Private Collection; (add.info.: The cong is of square cross section with rounded square corners and slightly tapers from top to bottom. The sides are divided into two registers with two different stylised mask at each of the four corners. Carved from a stone of glossy ivory-white tone.); Photo by Christie\'s Images.