As the cameo bears the image of St. John the Precurser, the patron of Tsar Ivan the Terrible, the item might be referred to as an icon having been executed specially for him.
Group of Authors of the Moscow Kremlin Museums. Decline of the Dynasty. The Last Rurikids and the False Dmitry. Moscow, 2021 Martynova M. Enamels of Moscow of the 15th – 17th centuries. Scientific catalogue. Moscow, 2002 Martynova M. Enamels of Moscow of the 15th – 17th centuries. Scientific catalogue. Moscow, 2002 Faith and Power. The Age of Ivan the Terrible. Moscow, 2007 The Armoury Chamber of Moscow Kremlin Museums. Album. Moscow, 2006