Tourmaline is the birthstone for October according to both the modern list, which is most actively used. Opal is the gemstone on the ancient list for October, but Tourmaline is the one most frequently used.
Pink tourmaline is the stone of a strong, independent person. If this is your stone, you're friendly, social and charming. You're the life of the party! You go out of your way to avoid confrontation and prefer harmony.