AN IMPORTANT ANTIQUE IMPERIAL RUSSIAN DIAMOND AND ENAMEL PRESENTATION PENDANT, 19TH CENTURY in yellow gold and silver, the oval pendant with an applied diamond set cypher of Tsar Nicholas I over a ground of blue guilloche enamel, within a frame of old cut diamonds, the bail set with further old cut diamonds, the diamonds all totalling 16.0-17.0 carats, no assay marks, 7
