onyx

Check out this Art Deco Design with Onyx and silver. 

Onyx is found worldwide but is most commonly found in Brazil, Madagascar and India. It has a mohs hardness value of 7. Onyx is the alternate birthstone for February. The name comes from the Greek word, onux, which means fingernail. Black Onyx is the most popular other colors are white, green, blue onyx, sardonyx and green onyx.

Onyx Information and metaphysical properties.
It is also the anniversary gemstone for the 10th wedding anniversary.
Some believe it to be a mystical birthstone for December.
Some believe that wearing black onyx repels negative thoughts and feelings,
Onyx is also considered as the lucky charm for the astrological sign of Leo.
Black Onyx is often heated to enhance the richness of color.
Black Onyx is also said to increase endurance.
Onyx is believed to have strong protective properties and guards against spells and curses from enemies.
It is also said that onyx enhances the wearers ability to enhance public speaking ability and romantic conversaton.