40004887, Marlborough, 736, Portrait (profile right): Socrates (?). Head of a bearded man, dress at neck. 'Socrates'., Walters Art Museum, Baltimore, Boardman, J., Scarisbrick, D., Wagner C., Zwierlein-Diehl, E: The Marlborough Gems (2009), Story-Maskelyne, M.H.: The Marlborough Gems (1870), 736, Cornelian