Sardonyx

Sardonyx is a variety of Agate where the banding lines are straight and parallel, and consistent in band size. The color of the bands are brown to red, and alternate with white or black bands. Sardonyx is a type of Onyx in which the color of the bandings is defined. In the gem trade, Carnelian is often incorrectly called Sardonyx.
Sardonyx is carved into ornamental figures, cameos, beads, and cabochons.