Metaphysical Properties:
Inspiration, understanding, confidence. Balances male/female energies and the mind. 
Black Tourmaline: Protects against negativity. Encourages intellectual thought, vitality. Corresponds to the root chakra, and the astrological sign Capricorn. 
Blue Tourmaline: Communication, psychic awareness. Corresponds to the throat and third eye chakras, and corresponds to the astrological signs Libra and Taurus