Black Tourmaline is the premier stone for grounding and protection. It is often one of the first stones people purchase, particularly when they become aware that they are susceptible to others' energy or are under psychic attack.
It is also helpful in strengthening your psychic shield, clearing your aura of negativity, and protecting from EMF's from electronic devices. Tourmaline is a stone of vitality and is excellent for moving all types of energy and providing energy to the user. It is also beneficial for balancing the brain and clearing the mind through rationality, releasing stress, and focusing on positivity.
The black color aligns with the Root Chakra, although it can work with other chakras, particularly the Sacral and Solar Plexus Chakras.
Roughly 2" x 1" (5cm x 2.5cm).