Tourmaline is believed to promote inspiration and happiness, reduce fear, and build self-confidence among its users. It's also used to balance yin-yang energies, as it's considered a physical bridge to the spiritual. Black Tourmaline crystal is a powerful stone for protection against negative energy of all kinds including psychic protection and EMF protection. It is also a strong spiritual grounding stone. ... It is one of the most popular crystals to be used for metaphysical purposes.