Tourmaline
Also called the rainbow gemstone, tourmaline was believed by the ancient Egyptians to have travelled along the rainbow gathering up its colours.
Scientific description classifies it as an aluminum borosilicate with prismatic striated crystals.
This October birthstone symbolizes thoughtfulness, courage, and generosity. It is thought by some to give permanence and stability to friendship and love.
According to Crystal Vaults, ancient magicians used Black Tourmaline, or Schorl, to protect them as they cast their spells.
Still valued as a talisman, this stone has the special characteristic of gathering a polarized electrical charge when it is heated or rubbed.