Tourmaline

Black Tourmaline is exceptionally grounding to the Earth's energies. It is a wonderful grounding crystal for meditation and healing. It soothes panic attacks, especially those caused by dark or confined spaces, or in places where the atmosphere is frightening. Wear this crystal for protection against those who burden you. 
In the workplace, hold Black Tourmaline for a few minutes when you need to wake up your mind or when you need full concentration. 
It provides an excellent shield against environmental pollutants, electromagnetic smog, and radiation associated with cell phones, computers, and other electronic equipment.