Pair of Carved Hardstone Plaques, China, each depicting a tale of the sacred oath by three legendary figures, Liu Bei, Guan Yu, and Zhang Fei, inscribed on reverse with date "Qianlong bingchen" (1736), stone of translucent spinach green mottled with spotty opaque streaks, in a frame decorated with openwork foliate scrolls, overall 29 3/8 x 20, plaque 23 1/2 x 14 1/4 in.