This is a stone of piezoelectric, meaning that it generates electricity under pressure, and pyroelectric, generating electricity with heat. Purifying and transforming dense energy into a lighter vibration, Tourmaline grounds spiritual energy: balances chakras, meridians, and auric bodies; and forms a protected field. Also a powerful mental  healer, balancing right and  left hemispheres of the brain and transmuting negative thought patterns into positive ones. (Judy Hall)

Chakra: Earth, protects all

Zodiac: Libra (varies according to color)