Black Stone

Black Black stones are receptive. They represent the Earth and stability and are ruled by Saturn, the planet of restriction. Black stones are symbolic of self-control, of resilience and quiet power. They are sometimes viewed as protective, but black stones are more often used to'earth' a person. If you're light-headed, dizzy, or so focused on the spiritual that your physical life suffers, wear black stones. Mystically, black is the color of the outer spaces, of the absence of light. If you wish to perform a spell of magickal invisibility, to ensure that your actions will not be noticed by others, use a black stone for this purpose. For example, make a small image of yourself out of black clay and adorn this with black stones. Place it in a black box or one made of mirrors, and then put the box in a dark place. This simply hides you from others if they represent a threat to your life.

[Encyclopedia of Crystal, Gem, and Metal Magic-Scott Cunningham]