The washer is carved in the form of a ram, with archaistic patterns to the body and incisions highlighting the swirling details on the beard and tail. The imperial reign mark is carved to the base, and the clear translucent stone appears to be flawless. 

Provenance: Nagel Auctions Stuttgart, 4 November 2011, lot 27.

Note: It is rare to find rock crystal carvings modelled in the form of archaic bronzes which depict mythical animals. A rock crystal vessel in the form of an archaic bronze guang, carved with chilong and dated to the Mid-Qing dynasty is in the collection of the Tianjin Museum of Art, illustrated in Zhongguo Yuqi Quanji - 6 - Qing, Hebei, 1991, p. 27, no. 44. 

It is interesting to see the four-character wheel-cut mark to the base of the current vessel, which is commonly associated with pieces made in the Imperial Palace Workshop for the Qianlong and Jiaqing emperors' courts. These types of mark appear less frequently on rock crystal carvings than those made from jade, indicating the high importance and superior quality of the current example. For a detailed discussion of imperial marks see Hugh Moss and Gerard Tsang, Arts from the Scholar's Studio, Hong Kong, 1986, p. 156.

Rock crystal is mentioned as an important material in historical Chinese texts dating to as early as the Tang dynasty (618-907), where it is described as a material made from water turned to stone (reflected in the Chinese term Shuijing or 'water crystal'), with suggestions of its import from Persia. Rock crystal objects typically appeared in the scholar's studio and by the 18th century, this pure stone was used to make carvings of exceptional quality for imperial consumption.  

Compare the present lot to rock crystal carvings from the Qing court collection, illustrated in The Complete Treasures of the Palace Museum - Small Refined Articles of the Study, Shanghai, 2009, no. 92, a mountain-form brush rest; no. 266, two mountain-peaked seals; and no. 281, a square seal paste box.