Onyx is a chalcedony quartz that is mined in Brazil, India, California and Uruguay that has a fine texture and black color; however some onyx also displays white bands or ribbons against a black or brown background. Onyx was very popular with the ancient Greeks and Romans. The name comes from the Greek word onyx, which means fingernail.
The legend is that one day Cupid cut the fingernails of Venus while she was sleeping and left the clippings scattered on the ground. So that no part of Venus would ever perish, the fates turned them into stone.
In Greek times, almost all colors of chalcedony from white to dark brown and black were called onyx. Later, the Romans narrowed the term to refer to black and dark brown colors only. Onyx which is reddish brown with white and lighter reddish bands is known as sardonyx. A 6.5 on the Mohs' scale, onyx is a very good stone for use in carving.
Most Black Onyx that is commercially available today is color enhanced (heated and dyed) to increase it's depth of color.
Thought to increase regeneration, happiness, intuition, instincts. Also thought to decrease sexual desire and helps to change bad habits.