Onyx is a black and white banded Chalcedony, a cryptocrystalline Quartz. It is often thought of as an all-black stone, and much of the black Onyx on the market has been artificially colored. Onyx has been both revered and feared throughout history. It is referenced in many sacred texts and historical manuscripts and is the first precious stone mentioned in the Bible. However in some regions, such as China, it was feared for centuries as a bad luck stone.