Black onyx is a variety of chalcedony quartz characterized by its polished black color and fine texture. It shines even more when set with other gemstones. Its fine texture makes it ideal for carving. It is popularly used in jewelry-making, especially in marcasite jewelry, and is often used as the black backdrop for highlighting colorful gemstones. Black onyx is believed to help eliminate stress, apathy, and neurological disorders.
