gems, engraved gems, agate, chalcedony, quartz, cameos, itaglios, turquoise, sard, onyx, coral, amethyst, glyptic

King concludes his examination of the Blacas collection with a survey of figures and groups on ancient and later engraved gems, followed by sections on Gnostic stones, cameos, and modern intagli. He discusses a wide range of mythological and religious subjects, including Bacchantes, Silenus and Bacchus, Hercules, Omphale, Diomedes, Prometheus, Apollo, Ceres, Cupid and Psyche, Medusa, and scenes connected with the Trojan cycle, assessing each according to style, workmanship, material, iconography, and probable date. Particular attention is given to the gemstones themselves, including sard, sardonyx, amethyst, plasma, jasper, jacinth, agate, emerald, turquoise, and antique glass pastes; notable examples include a deep-green plasma resembling emerald, an actual emerald engraved with Jupiter and Antiope, a pale-green antique paste imitating peridot, a Medusa carved from a large Peruvian emerald, and a rare green turquoise cameo depicting the Indian Bacchus. King also examines Gnostic and magical gems combining Egyptian, Mithraic, and astrological imagery, while noting the relatively poor representation of Assyrian, Persian, and Sasanian glyptic art in the collection. A substantial portion of the article is devoted to cameos, particularly imperial portraits, whose traditional identifications King frequently challenges through comparison of physiognomy, style, technique, and historical evidence. Most notably, he reidentifies the celebrated cameo traditionally called Constantine Junior as Augustus, arguing that its jeweled diadem was a Byzantine modification replacing an original laurel wreath. He likewise questions identifications of Livia, Licinius, Ptolemaic rulers, and other portraits and repeatedly distinguishes genuine ancient works from Renaissance and modern imitations. The final section treats Renaissance and later glyptic masterpieces associated with Matteo del Nassaro, Giovanni dal Castel Bolognese, Valerio Vicentino, Pichler, and other engravers, including the celebrated rock-crystal intaglio of Tityus and the Vulture, engraved by Giovanni from a design by Michelangelo. Throughout, King combines description with critical connoisseurship, using stone type, cutting technique, inscriptions, iconography, provenance, literary testimony, and comparison with coins and other works of art to assess attribution, date, and authenticity.