sardonyx
/ˈsɑrdənɪks/
noun
- A gemstone with alternating layers of sard (a reddish-brown chalcedony) and onyx (a black-and-white banded chalcedony), often used in jewelry and cameos.
- Ancient Roman artisans carved intricate cameos from sardonyx.
- She wore a ring set with a polished sardonyx that showed bands of red and white.
- The jeweler explained that sardonyx is believed to bring courage and protection.