Black Onyx is a highly coveted gemstone, incorporated into several forms of jewelry not just because of its translucent outer coating and sophistication but because of the healing properties that are associated with it. Black Onyx falls under the family chalcedony quartz. The mineral hardness is between 6.5 and 7 using the Mohs scale.
Throughout history it has not only been cut into jewelry in the form of rings and bracelets but it's been used in public spaces as decoration for things like statues, particularly the jewelry that is worn by statues or the eyes that are carved into statues.
Onyx only forms in bedrock openings or caves and is mined in many colors, like black, red, blue, yellow, green, and brown. Black Onyx has been excavated from several areas around the world, including Arizona, in the United States, China, Argentina, India, Indonesia, Germany, Brazil, Uruguay, and Canada.
While black Onyx is a naturally occurring gemstone, you can find artificially colored black Onyx that doesn't appear to contain the same natural lines or layers and instead has a pure dark black color to it, though natural occurrences of this are rare.