Prendeville, J.: Explanatory catalogue of the proof-impressions of the antique gems possessed by the late Prince Poniatowski and now in the possession of John Tyrrell, Esq. (1841): 23
The Wellington Gems (1977) [London, Market, S.J. Phillips]: 419.9
Comments: SET IN AN AMETHYST NECKLACE WITH TWELVE CAMEOS AND INTAGLIOS