Sardonyx

Sardonyx is a striking variety of onyx that features parallel bands of brownish-red Sard and white or black Onyx. This unique layering creates a highly graphic, "striped" appearance that has been prized since antiquity. Historically, Roman soldiers wore Sardonyx talismans engraved with the image of Mars (the god of war) to bring courage and protection on the battlefield.

Unlike more common agates, the banding in Sardonyx is remarkably straight and distinct. Because of these clean layers, it has remained the premier material for the art of cameo and intaglio carving, where the different colored layers are utilized to create 3D-effect portraits and symbols.