Jade blades of this form carved with teeth-like notches are called yazhang in Chinese, a term first used by the eminent late Qing dynasty scholar collector Wu Dacheng (1835-1902) in his book Guyu tukao [Study of ancient jade]. Yazhang made its first appearance during the Neolithic period, although as noted by Jessica Rawson, large jade blades of this form have no prototypes among the stone implements of the Neolithic period and the source of this shape remains unknown, (see Jessica Rawson, Chinese Jade from the Neolithic to the Qing, London, 1995, p. 188). The production of yazhang was popular in the Xia and Shang dynasties and the distribution of this blade type is surprisingly wide, including Shandong, Shaanxi, Henan, and Sichuan.
The function of yazhang has been an area of discussion and interpretations of it as a military implement have been suggested in ancient texts such as Zhouli [Rites of Zhou], as well as Zheng Xuan's commentaries in the Eastern Han dynasty. Blades of this form are often of large size and are finely and thinly carved suggesting a ceremonial function, which is consistent with the archaeological excavation findings of yazhang from sacrificial pits.
Compare a slightly larger yazhang of this type, attributed to Neolithic period, in the National Museum of China, Beijing, illustrated in National Museum of China, ed., Zhongguo Guojia Bowuguan guancang wenwu yanjiu congshu. Yuqijuan [Studies on the collections of the National Museum of China. Jade], Shanghai, 2007, pl. 25; one from the collection of George Coe Graves, attributed to the Neolithic period to Shang dynasty, now in the Metropolitan Museum of Art, New York, acc. no. 30.120.124; a third from the collection of David David-Weill, sold in our Paris rooms, 16th December 2015, lot 14; another from the Arthur M. Sackler Collection, attributed to late Xia or early Shang dynasty, sold at Christie's New York, 1st December 1994, lot 87; and one of a slightly smaller size, from the Hongshan culture, discovered in Haiyang, Shandong province, illustrated in Gu Fang, The Complete Collection of Unearthed Jades in China, vol. 6, Beijing, 2005, p. 34;