Onyx is the birthstone of december.
Onyx is believed to be a stone of strength and lends stamina to the wearer. It is also said to be good for past life work, especially if trying to trace the source of an unknown injury. Onxy is also thought to channel the healing energies of the universe so the wearer can use it to heal themselves or others. Onyx is also said to help grief, enhance self-control and stimulate the power of wise decision-making & encourages happiness and good fortune.