1. (Undated Folder Sheet note) Trapezoidal in shape, this ornament is fashioned from a thin slab of mottled tan-colored jade. While the overall symmetrical silhouette of the ornament reflects an impressive degree of sophistication, especially in the relationship of the concave and convex surfaces, the perforated decoration was achieved with surprising crudeness. It is apparent that the Chinese artisan drilled a series of small holes through the jade slab and then connected them to form the irregular reticulated pattern.
A more elaborate jade ornament of this type was unearthed in one of the royal Shang 商 tombs at Houjiazhuang 侯家莊, Henan 河南 province, in the early years of the twentieth century (see Zheng Dekun, Archaeology in China vol. II [Cambridge: W. Heffer and Sons, 1960], pl. XX:a). That jade ornament, usually described as a headdress decoration, displays the same curious contrast between its complex silhouette and crude perforations. Nonetheless, the appearance of the jade headdress in a royal tomb suggests that it was regarded with esteem, even though most of the jades from the royal Shang 商 tombs in the area of Houjiazhuang 侯家莊 display considerably more technical skill in their decoration.
2. (Jeffrey Smith per Keith Wilson, July 17, 2008) Jewelry added as secondary classification.
3. (Jeffrey Smith per Janet Douglas, June 17, 2010) Nephrite added as modifier to existing medium of "jade" based on conservation analysis.
4. (Najiba Choudhury per Keith Wilson, August 17, 2016) Date changed from "ca. 2nd millennium BCE" to "ca. 1600-1050 BCE"; description, past label text, and unpublished research added; title changed from "Ornament with mask" to "Ornament in the form of a mask (shi 飾)".
5. (Jeffrey Smith per Keith Wilson, May 10, 2018) Geography edited to just "China" from "Houjiazhuang, Henan province, China."
Draft catalogue entry for S1987.514; by Jenny F. So (2003)
Late Neolithic or Bronze Age, 2nd millennium BCE
Middle or upper Yangzi 揚子 river valley
Nephrite, gray-green with brown patches
W 18.75 × H 6.10 × 0.50--0.57 cm thick
Former Abel William Bahr collection
A broad trapezium describes the rough outline of this large plaque. The corners at the wide top turn down in hooked scrolls echoed by a smaller projection below them. A low, flared crest rising to a point in the middle marks the center of the top, evoking the silhouette of jade comb tops from Liangzhu 良渚 contexts (see F1917.382). Five openwork areas pierce the flat surface of the plaque: a small cross-shape below the crest, followed by a pair of long angular downward facing C-scrolls and two slightly upward curving slits, both arranged symmetrically on either side of the median axis. A tiny hole pierces the axis just below the curved slits.
Drilling holes along the length of the openwork and then removing the connecting bit between the holes by rope produce the openwork areas. This leaves a distinctively uneven edge to the openwork spaces. Faint broken incised lines are just visible along edges of some of the openwork spaces, sketched in as if in preparation for more designs that were unexecuted. The method in which the openwork is done is typical of those used on Neolithic jades from the lower Yangzi 揚子 valley.  This method is used on examples from early Liangzhu 良渚 sites such as Zhanglingshan 張陵山 (fig. 1).  The sketchy incised lines that follow the outlines of the openwork appear also on openwork examples from later contexts in Shandong 山東 and Hunan 湖南. 
A plaque with a similar design but not as large, in the collections of the Seattle Art Museum (39.9), shows the same sketch lines, as does a smaller example recovered from Shijiahe 石家河 contexts at Liuhe 六合, Zhongxiang 鈡祥, Hubei 湖北 province (fig. 2).  The Sackler and Seattle plaques have been regarded as greatly abstracted images derived from the large family of mask-like images, including examples from Shijiahe 石家河, that has attracted much discussion (see S1987.880).  An alternate reading sees it as a highly abstracted version of the feline motif also recovered among Shijiahe 石家河 jades.  Regardless of its formal derivation, its close association with the Shijiahe 石家河 context would suggest a date toward the end of the third and beginning of the early second millennium BCE. 
The similarities in form and execution of the excavated examples cited above to the Sackler and Seattle plaques suggest a route of dissemination that began in the Neolithic communities in the lower Yangzi 揚子 valley. From there, the technique and the form went upstream to the middle Yangzi 揚子 valley, and eventually reached the upper reaches of the Yangzi 揚子 river, where the outlines of the Sackler plaque are reproduced on a bronze plaque from Sanxingdui 三星堆, Guanghan 廣漢, in Sichuan 四川 province (fig. 3). The spread of this motif upstream following the Yangzi 揚子 river has been seen as archaeological corroboration of the historical dispersal of the "San Miao 三苗" (the Three Miao 苗 tribes of eastern China, presumably including the Liangzhu 良渚 peoples) during the time of the third millennium BCE. 
Published: Doris J. Dohrenwend, "Jade Demonic Images from Early China," Ars Orientalis 10 (1975), fig. 1; Hayashi Minao 林巳奈夫, Chūgoku kogyoku no kenkyū 中國古玉の研究 (Tokyo: Yoshikawa kōbunkan, 1991), fig. 5-23; Yang Jianfang 楊建芳, Zhongguo guyu yanjiu lunwenji 中國古玉研究論文集 = Treatises on ancient Chinese jades, vol. 1 (Taipei: Zhongzhi meishu chubanshe, 2001), fig. 6:9.
1.Zhanglingshan 張陵山 fitting (Zhejiang sheng wenwu kaogu yanjiusuo 浙江省文物考古研究所, Shanghai shi wenwu guanli weiyuanhui 上海市文物管理委员会, and Nanjing bowuyuan 南京博物院, Liangzhu wenhua yuqi 良渚文化玉器 [Beijing: Wenwu chubanshe and Hong Kong: Liangmu chubanshe, 1989], no. 203).
2.Liuhe 六合 plaque (see Jingzhou diqu bowuguan 荊州地區博物館 and Zhongxiang xian bowuguan 鈡祥縣博物館, "Zhongxiang Liuhe yizhi 鈡祥六合遺址," Jianghan kaogu 江漢考古 1987.2, pl. 4:8).
3.Bronze plaque from Sanxingdui 三星堆.
 For good examples of this method at work from Liangzhu 良渚 contexts, see Zhejiang sheng wenwu kaogu yanjiusuo 浙江省文物考古研究所, Shanghai shi wenwu guanli weiyuanhui 上海市文物管理委员会, and Nanjing bowuyuan 南京博物院, Liangzhu wenhua yuqi 良渚文化玉器 (Beijing: Wenwu chubanshe, and Hong Kong: Liangmu chubanshe, 1989), nos. 159, 160, 220.
 For another early example from Zhanglingshan 張陵山, see ibid., no. 231.
 Zhongguo shehui kexuyuan kaogu yanjiusuo Shandong gongzuodui 中國社會科學院考古研究所山東工作隊, "Shandong Linqu Zhufeng Longshan wenhua muzang 山東臨朐朱封龍山文化墓葬," Kaogu 考古 1990.7, pp. 587--94, pl. 2:1.
 The Seattle example is published in Doris J. Dohrenwend, "Jade Demonic Images from Early China," Ars Orientalis 10 (1975), fig. 2; the Liuhe 六合 find is published in Jingzhou diqu bowuguan 荊州地區博物館 and Zhongxiang xian bowuguan 鈡祥縣博物館, "Zhongxiang Liuhe yizhi 鈡祥六合遺址," Jianghan kaogu 江漢考古 1987.2, pp. 1--31.
 For example, Doris J. Dohrenwend, "Jade Demonic Images from Early China," Ars Orientalis 10 (1975), pp. 55--78; Wu Hung 巫鴻, "Yizu zaoqi de yushi diaoke 一組早期的玉石雕刻," Meishu yanjiu 美術研究 1979.1, pp. 64--70; Hayashi Minao 林巳奈夫, "Sen In shiki no gyokki bunka 先殷式の玉器文化 = Patterns on Pre Yin Jades," Museum 334 (1979), pp. 4--16.
 Yang Jianfang 楊建芳, Zhongguo guyu yanjiu lunwenji 中國古玉研究論文集 = Treatises on ancient Chinese jades, vol. 1 (Taipei: Zhongzhi meishu chubanshe, 2001), pp. 62--63.
 Hayashi Minao 林巳奈夫, Chūgoku kogyoku no kenkyū 中國古玉の研究(Tokyo: Yoshikawa kōbunkan, 1991), pp. 376--77, also supports this dating. Yang Jianfang 楊建芳 in Zhongguo guyu yanjiu lunwenji 中國古玉研究論文集 = Treatises on ancient Chinese jades, vol. 1 (Taipei: Zhongzhi meishu chubanshe, 2001), p. 62, prefers to see the Sackler plaque as the latest in the series, comparing it to an example from Anyang 安陽 and dating it to the late Shang 商 period. Yang's dating seems a trifle late for the technical and formal evidence cited above.
 Argued in Yang Jianfang 楊建芳, Zhongguo guyu yanjiu lunwenji 中國古玉研究論文集 = Treatises on ancient Chinese jades, vol. 1 (Taipei: Zhongzhi meishu chubanshe, 2001), pp. 70--80.
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