The diamond is said to possess great virtues. It guarantees victory to the possessor when bound to on the left arm no matter the number of his enemies. Panics, pestilences, enchantments, and whatever all fly before it; hence, it is good for sleepwalkers and the insane.
It deprives the loadstone of its virtue, and one variety, the Arabian diamond, is said to attract iron more powerfully than the magnet itself. The ancients believed that neither fire nor blows could overcome its hardness; and Cryprian, Austin, Isidore, and others of the fathers, adopting this notion, have used it to illustrate the method by which the blood of the Cross softens the heart of man.
If bound to a magnet, the diamond, according to ancient beliefs, deprives the magnet of its virtue or power.
Supposedly the diamond helps coughs, mucus, the lymph system, toothache, insomnia, and convulsions. (see Gem Healing) A.G.H.