Black Onyx is a variety of chalcedony, a type of quartz, known for its deep black color. Formed from silica deposits in gas cavities of lava, it is found in countries like Brazil, India, and the United States. Types of onyx include banded onyx, sardonyx, and plain black onyx.
Benefits: Traditionally, wearing black onyx is believed to offer protection, absorb negative energy, and promote emotional strength, though these benefits are based on folklore and not scientifically proven.