Onyx is a stone of strength, supporting and assisting you. It is a stone of personal and physical strength, a stone of mental and emotional strength, and of course, a stone of spiritual strength. It is an especially good stone for those going through rough times, mental or physical stress, or confusing circumstances. Onyx is said to centre your energy.
A stone of Self-Mastery, it can help you to gain more control of your own mind, and also to focus your will - this increases one's personal power. In healing, Onyx is said to be used for teeth, bones, bone marrow, blood disorders, and the feet. Black Onyx aligns with the Base Chakra.