Tourmalinated Quartz is clear rock crystal (crystal quartz) which has grown together with black tourmaline, and shows strands of the tourmaline running through the quartz, hence "tourmalinated."
From Brazil
Tourmalated Quartz Tower
Tourmalinated quartz is believed to protect the wearer from negative thoughts and emotions. It is said to be filled with energy that flashes through it and connects one with other fields of energy. Tourmalinated quartz is thought to provide a balancing of yin/yang energies and release negative patterns. It is used by some to treat disorders of the digestive tract and to detoxify the body. Tourmalinated quartz is aligned with the Zodiac signs Libra, Capricorn and Scorpio. It is associated with the 6th, Third Eye or Brow Chakra, but is also believed to be effective on the secondary chakras of the hands and feet, including the meridians.