A

David

Darling

onyx

onyx

A sample of brown onyx from Iran.


Onyx is a variety of chalcedony with variegated bands, straight rather than curved as in agate. Sardonyx has white and brown bands; carnelian onyx white and red. Onyx is used as a gemstone, especially for cameos and intaglios. It is widely distributed but found mostly in India and south America.