This precious stone is known for the energy of strong support, stamina, and determination to help one's persevere. It is said to teach the wearer to rely on own powers; which is then often crafted as traditional wealth bracelets and amulets. This Crescent  shaped Black Onxy Piece measures 3.5cm diameter approx. It is suspended from an 20 Inch 925 Silver chain. Onyx is the birthstone for Leos and the anniversary gemstone for the 7th year of marriage. Black Onyx is the anniversary gemstone for the 10th year of marriage. Onyx is a variety of the microcrystalline quartz, called chalcedony.