σαρδόνυξ

A. sardonyx, Philem. 216, Gal. 5.46, AP 1.116, J. AJ 3.7.5, BJ 5.5.7, Apoc. 21.20, Ps.-Plu. Fluv. 20.4, etc. The stone was called ὄνυξ when the dark ground was simply spotted or streaked with white, but σαρδόνυξ if the different colours were disposed in layers.