40005023, Marlborough, 376, Portrait (frontal): Caracalla (?). Frontal head of Caracalla with added bust wearing corselet and cloak., Unknown, Boardman, J., Scarisbrick, D., Wagner C., Zwierlein-Diehl, E: The Marlborough Gems (2009), Story-Maskelyne, M.H.: The Marlborough Gems (1870), no. 376, Cameo, White oriental alabaster