Onyx is a variety of Agate. Onyx is either solid black or has black and white bands. Onyx that is reddish brown and white is known as Sardonyx. Black onyx is usually dyed to produce a uniform color. Onyx has a fine texture that makes it ideal for carving cameos. In ancient times Romans used onyx to carve their seals because wax would not stick to it.
This black onyx necklace has tiny black onyx beads woven over a rubber collar with a magnetic clasp. This necklace can be worn alone with the clasp in back or with the clasp in front with a ginkgo leaf pendant (shown above) or one of the many V-style silver pendants available at SilverStones.
The main source of onyx is British Columbia, Canada, Scotland, UK and in the US in Utah, South Dakota, Idaho and Rhode Island, although it is also found in other parts of the world.