The cameo is carved from an amber-colored stone (sardonyx) that has a white upper layer. At the center, Hercules accomplishes his eighth Labor – capturing the flesh-eating horses of Diomedes, king of Thrace. The hero stands frontally, grasping the mane of a rearing horse with his left hand, while brandishing his club over Diomedes, who collapses on his knees at left.
Hercules’ nude body is carefully articulated to emphasize his musculature, and a lionskin knotted over his chest covers his head. He is beardless, in contrast to Diomedes, who grasps Hercules’s right leg with his left hand. The defeated king wears trousers and a cap, and has a sword in its scabbard at his hip. He extends his right arm (now missing), and a bow and quiver containing two arrows lies on the ground at left.
The cameo was once in the famed collection of Lorenzo de‘ Medici (1449-1492) in Florence. Lorenzo’s ownership mark is partially preserved in Latin above Hercules. The copper-rich gold pendant in which the cameo is set has a decorative guilloche border, and dates to the nineteenth century.