40005021, Marlborough, 216, Portrait (profile left): Caracalla. Laureate bust of a young man. 'Young Caracalla'., Unknown, Boardman, J., Scarisbrick, D., Wagner C., Zwierlein-Diehl, E: The Marlborough Gems (2009), Story-Maskelyne, M.H.: The Marlborough Gems (1870), no. 216, Cornelian