Some (but not all) birthstone lists include sardonyx as a birthstone for August. Sardonyx is a banded variety of chalcedony that exhibits straight, parallel bands of white, black, orange, red, or brown chalcedony. Some of the most spectacular cabochons and beads are cut from sardonyx.

Sardonyx has also been used as a material for cutting cameos. These take advantage of the layered, multicolored nature of the material. Cameos have been popular in jewelry for at least 2000 years. (Cameos are often cut from many other materials, especially shell materials, but many of the finest cameos are cut from sardonyx.)