Black Sardonyx (a variety of Chalcedony) is a very grounding and protective stone. It strengthens one's willpower and courage while increasing one's stamina and self control. This crystal is great for strength, vitality, courage, power, self-discipline, protection, motivation, leadership, and mastering fear.
Astrological Sign: Aries, Leo
Chakras: Brow, Sacral, Throat, Root
Planetary Alignment: Mars, Mercury