40005016, Marlborough, 536, Facing portraits (profile right and left). Julian and Helena (Bernoulli), Commodus and Crispina (King), Marcus Aurelius and Faustina (Story-Maskelyne), Claudian period (Furtwängler). The confronted busts of Jupiter-Ammon (oak wreath and curled horns) in armour, and Juno-Isis (oak wreath with fruit; fringed dress fastened with nodus Isiacus). The lower shoulder of the male is missing., Unknown, Boardman, J., Scarisbrick, D., Wagner C., Zwierlein-Diehl, E: The Marlborough Gems (2009), Story-Maskelyne, M.H.: The Marlborough Gems (1870), no. 536, Cameo, Sardonyx