Onyx is a variety of Chalcedony, a member of the quartz family. It has a hexagonal crystal system and a hardness of 7. Onyx is recognised as a banded Chalcedony with the bands being parallel to each other.
Onyx is the stone of inner strength and is said to enhance one's endurance and persistence, enhance willpower and increase one's ability to maintain focus, helping them to not only learn a new challenging task, but to master it. It is believed to energetically boost memory retention and encourage attention to detail. It can help one to focus and direct their will which in turn can considerably increase one's personal power. Onyx condenses and cools excessive energies, calms nervousness, quells anxiety, soothes a hot temper and brings reason to passion.