While it is not actually diamond, it is a quartz that often resembles the sparkling clarity of diamonds.
It can be metaphysically programmed to attuned one to an environment, a situation, a quality or most anything.
It is said to assist with balance on the mental, emotional and physical levels. It can be used effectively to clear and open any chakra.
It is professed to relieve tension and thereby promote peace of mind. Psychically, it's useful for auric cleansing and dream recall.