Genuine Black Onyx is an opaque black stone that can be polished to a mirror smooth finish. A lot of 'Black Onyx' available on the market is actually dyed Agate and the easiest way to tell the difference is to hold your stone to the light. If it is black and opaque you probably have genuine Onyx. If it is translucent or you can see banding in the stone you probably have dyed Agate.

Black Onyx has always been associated with magic, and some say the stone is in tune with the darker side of magic and sorcery. An unscrupulous person could use Black Onyx in sorcery to cause nightmares or destroy friendships and partnerships, but it is worth remembering that any stone used in magic is neutral until a person projects their own malicious energy into it.

Black Onyx is very protective and is believed to bring good luck to its owner as well as guarding them against spells and curses and rebounding or 'mirroring' negative energy back to the person who sent it. It can also be used to increase endurance and bring hope, even in the darkest depths of despair.