Onyx is the birthstone for Leos Onyx is a variety of the microcrystalline quartz, called chalcedony. The name "chalcedony" comes from Calcedon or Calchedon, an ancient port on the Sea of Marmara in Asia Minor. Black Onyx meaning is Self-control, decision making, intuition, protection. It is widely believed that black onyx can change your habits are erratic, either when used with faith. It is regarded as one powerful protection stone as it absorbs negative energy of people to release mental stress and promote emotional well-being. Black Onyx is associated with the planet Saturn, which will bring a positive vibe for those born in the shadow of the planet Saturn. It is a stone for Leo zodiac sign. Black Onyx stone will helps maintenance Leo characteristic. Black Onyx meaning In the Indian tradition is said to help people to forget about their past relationships and bring people in tune with the present.