1. a type of quartz with bands of different colors, often black and white, used for making jewelry and decorative objects

Examples

• The ring featured a beautiful black onyx stone.
• She wore onyx earrings that matched her dress perfectly.
• The ancient Greeks carved cameos from onyx.
• The fireplace was decorated with green onyx tiles.
• His cufflinks were made of polished white onyx.
• The museum displayed an onyx vase from ancient Rome.