gems, corundum, History.1, Roman jewelry; diadem; necklaces; Herculean knot; sapphires; pearls; long-distance Roman trade

A piece of jewelry consisting of twenty-five gold links in the form of Herculean knots arranged vertically was discovered in 2011 at Colonna (Rome) inside the sarcophagus of a complex female burial—a tomb with an inaccessible hypogeal chamber, dated to the late 2nd century CE. The object is 29 cm long, and all the links were designed to receive a secondary element, which survives in only seven cases: seven sapphires, totaling 46.20 carats. The complete absence of the other eighteen elements and their mounting system strongly suggests that they were pearls. To date, this ornament is unique among jewelry found in the territories of the Roman Empire. Chain necklaces with links in the form of simple Herculean knots—arranged horizontally—alternating with fixing-links strung with gems (mostly emerald prisms) are known in Roman jewelry thanks to their discovery in hoards dated to the 3rd century CE. The length of the object from Colonna and its position within the sarcophagus, near both the head and neck, suggest that it is one of the rare head ornaments attested in the 2nd/3rd century CE in the western provinces of the Roman Empire in high-status female burials, consisting of a diadem worn across or above the forehead, from ear to ear. The style of the diadem from Colonna, which particularly suits Antonine-era hairstyles, suggests that the piece was created between the early 140s and the mid-160s CE. Some final remarks are reserved for a possible symbolic interpretation of the form—already highly decorative in itself—of the Herculean knot.