This circular jade disc with central hole characterizes the ritual shape known as bi as cited in later ritual texts of Eastern Zhou and Han date. This version, with inner and outer edges well polished and rounded, is based on the earlier prototype found in large numbers in Liangzhu culture burials of late Neolithic date. However, the smooth working of the edges and the symmetrically balanced width more likely indicates a post Liangzhu date, perhaps as early as Longshan or early Shang date or as late as Eastern Zhou

Very few bi from post-Liangzhu period tombs have been excavated. One very small example comes from Daisikongcun at Anyang, Kaogu xuebao:9, 1955, p. 55, pl. XVIII:1. According to the archaeological report on M5 (Fu Hao burial) at Anyang, sixteen bi were found, Yinxu Fu Hao mu, Beijing, n.d., pp. 118-19. All of the latter are extremely small, half the diameter or less of the present example

A close comparison to the Sackler piece belongs to the collection of the late William H. Miller, Jr. of New York, Childs-Johnson, Ritual and Power: Jades of Ancient China, China Institute in America, New York, 1988, fig. 11, p. 17. Another comparably close bi that has an excavated context and dates to the Longshan period comes from the Yanan district in Shaanxi, The Complete Collection of Chinese Jades, vol. 9, 1992, pl. 46

Compare, also, the similar bi of comparable size (22cm. diam.) dated to the Neolithic period in the Peony Collection included in the exhibition, Jades from China, The Museum of East Asian Art, Bath, England, 1994, Catalogue no. 58. Another similar bi of slightly smaller size (20.4cm. diam.) is in the Illustrated Catalogue of Ancient Jade Artifacts in the National Palace Museum, Taipei, 1982, no. 184, where it is ascribed to the Han dynasty