The oval mosaic with small tesserae, executed with extreme care, is contained in a copper setting with, on the back, the engraved signature: “VINCENTIUS CASTELLINI. ROM. FECIT”, the whole in turn enclosed in a rich gilt bronze frame by the goldsmith Paolo Spagna.
The frame is composed of several orders of vegetative motifs enriched by others with beading.
Above, the coat of arms of Pius VI (Braschi 1775 – 1799) and flanked by two winged sirens and supported by cornucopias. Four cherubs, gracefully gesticulating, are set either side of the Pope’s coat of arms.