The Wellington Gems (1977) [London, Market, S.J. Phillips]: 420.2
Comments: SET IN A NECKLACE WITH ELEVEN INTAGLIOS. See also the drawing in the Museo Poldi Pezzoli, by Vimercati Sozzi Paolo (1801/ 1883), a design by Beltrami. Other gems are copies from the Poniatowski collection. http://www.lombardiabeniculturali.it/opere-arte/schede/2o050-00165/