Post-Erlitou or Early Shang in date, probably Zhengzhou period, ca. 1700 B.C. A handsome variation of the earlier, Xia period royal type of insignia called zhang, see E. Childs-Johnson, "Dragons, Masks, Axes and Blades", Orientations, April, 1988, pp. 30-41, figs. 35-6; and Ritual and Power: Jades of Ancient China, China Institute in America, New York, 1988, nos. 38 and 39. The Xia (ca. 2100-1700 B.C.) witnessed the perfection of this worked jade insignia, as told by large-scale jade zhang from tombs at Erlitou, Henan Province, see Kaogu, 1978:4, fig. 2, p. 270; and Wen Fong, ed. The Great Bronze Age, New York, 1981, pl. 2. The present example is datable to a post-Erlitou period of production when the robust shape of trumpet-shaped mouth and faceted haft are modified to a simple rectangular handle and gently arched mouth. Based on current archaeological data, zhang gradually disappear as a major art form during the Shang, see, for example, the 183 stone zhang unearthed from 41 of 100 small burials in the Western Sector Cemetery of Yinxu (Anyang), published in Kaogu xuebao, 1979:1, fig. 79:1 left, description p. 105. The latter are all crude, less than 15cm. long blades with one blunt and one oblique end. The pierced hole on the haft indicates where a handle would have been attached to the blade and its predecessor tool

Very similar zhang of Erlitou and post-Erlitou/early Shang date are illustrated by Una Pope-Hennessy, Early Chinese Jades, New York, 1923, pl. XXV (fig. 1); in the Sonnenschein Collection, Salmony, Archaic Chinese Jades, Art Institute of Chicago, 1952, pl. XXVII:2; and in the Winthrop Collection, Fogg Art Museum, Max Loehr, Ancient Chinese Jades, Cambridge, Massachusetts, 1975, nos. 219-110 and 223-227