Note: This unusual and rare mask is remarkable for its expertly carved and finished features, from the pointed eyes to the round nose, and the menacing fangs and teeth. Its attribution to the Longshan culture in Shandong is discussed by Angus Forsyth and Brian McElney in the catalogue to the exhibition Jades from China, op.cit., p. 154, where the incised mask on the reverse of this piece is compared to the incised design on a jade axe from the Grenville L. Winthrope collection, now in the Arthur M. Sackler Museum, Harvard University Art Museums, Cambridge, illustrated in Max Loehr, Ancient Chinese Jades, Cambridge, 1975, pl. 192.

This mask also share similarities with anthropomorphic jade carvings attributed to the Shijiahe culture in Hubei province, such as two masks unearthed at Xiaojiawuji, Tianmen, illustrated in Gu Fang, The Complete Collection of Unearthed Jades in China, Beijing, 2005, vol. 10, pls 2 and 3, together with one excavated at Luojia Bailing, Tianmen, pl. 30; one excavated from the Western Zhou tomb at Zhangjiapo, Chang'an, Shaanxi province, but attributed to the Shijiahe culture, illustrated in Jessica Rawson, Mysteries of Ancient China, London, 1996, pl. 54; another from the collection of Henry J. Oppenheim, now in the British Museum, London, illustrated in Roger Keverne (ed.), Jade, op.cit., pl. 47; and a further mask attributed to the latter years of the Shijiahe culture, included in Collectors' Exhibition of Archaic Chinese Jades, National Palace Museum, Taipei, 1995, cat. no. 18. See also a mask attributed to the Longshan culture, in the Shanghai Museum, illustrated in Shanghai Museum. Ancient Chinese Jade Gallery, Shanghai, 2000, p. 11 (bottom).