onyx

/ˈɑnɪks/

/ˈɒnɪks/

Other forms: onyxes

Onyx is a a semiprecious stone with alternating black and white bands. It's often used in jewelry.

Onyx is a chalcedony, which is a type of natural stone formation composed of intergrown minerals. In the case of onyx, the colors appear in bands, mainly in black and white. Onyx is considered very attractive and it's commonly used in jewelry. It's very likely you've seen earrings or a necklace made from onyx. You might also see a trophy made from onyx, with something engraved on it. Natural formations like onyx are studied by geologists.

Definitions of onyx

1. noun

   a chalcedony with alternating black and white bands; used in making cameos
   types:

   sardonyx

   an onyx characterized by parallel layers of sard and a different colored mineral

   type of:

   calcedony, chalcedony

   a milky or greyish translucent to transparent quartz