Properties: In addition to the general properties for black tourmaline, tourmaline often occurs with mica. Because of mica’s reflective qualities, it is believed to deflect any negative energies or intent away from the holder to be transmuted into something benign and positive (or return to the sender to act as a lesson in some systems). Mica is used as an insulator in the electrical industry, and can further enhance black tourmaline’s ability to dampen electromagnetic radiation.