Onyx is a banded variety of the mineral chalcedony. It is formed from deposits of silica in water filtering through fissures in other rocks. Onyx and agate are both formed this way, but are classified by their bands: agate’s bands are curved while onyx has parallel bands across its surface.
These bands gave onyx its name. The light shade of the band across the stone reminded ancient Greeks of a fingernail, hence “onyx” coming from the Greek word “onux” or “claw.”
• While black onyx is the most well-known variety of onyx, it is not the most common to occur naturally. In fact, most black onyx commercially available is artificially dyed by soaking or boiling and applying a chemical treatment. Your specimen has not been artifically colored.
• Onyx has been used for decoration throughout history. Legend has it that Cleopatra wore black onyx as a protection charm, claiming that the mineral would vibrate when she was near her enemies.
• Add this sample to your geology collection.
This is a listing for one black onyx specimen. Please note that you will receive a specimen similar to the images shown. Size ranges from .5" to 2". Larger specimens will be prioritized first.