A rectangular plaque carved with a similar dragon and clouds, dating the Yuan dynasty (1279-1368) is illustrated by Mei Ninghua and Tao Xincheng in Gems of Beijing, Cultural Relics Series, Jades, 1999, no. 123, p.128.
Also compare the current lot to another shaped dragon plaque from a buckle, illustrated by Yang Boda in Zhong Guo Yu Qi Guanji (The Collection of Chinese Jade), Vol. 5, no. 199, p. 133.