Often known as Black Schorl, the dark variety of tourmaline has a strong reputation for its holistic effects. It is composed of an array of different substances and was sometimes referred to as the "Sri Lankan Magnet". Dutch traders called it "Aschentrekker" or "ash puller" as they often used tourmaline to clean ash from their pipes. This is because tourmaline is a pyroelectric mineral, meaning that when heated, black tourmaline will acquire a voltage due to the polarization of charges within the crystal structure. This is similar to the voltage that a quartz crystal acquires when mechanical pressure is applied to it. This means that black tourmaline feeds on ambient heat, and entropy. In addition, the black color we see in this crystal is due to the absorption of the entire visible spectrum of light by the crystals' structure.
Overall this makes black tourmaline perfect for pain relief, clearing your aura, and protecting your personal space. As a grounding stone, it brings you back to your inner self. It shows that the greatest strength lies in the inner, dark foundation that gives birth to the light we all see. There is no better stone for inner reflection, and work related to the shadow realm of your own psyche. Therefore, if you want to know yourself on a deeper level, black tourmaline is the stone to keep!