Tourmaline phenomenon often with visible characteristics. Colorless streak. Glass sheen. Without dissociation. Hardness mare. With brittle. The proportion of 3.***3.*5. With piezoelectric and pyroelectric properties. UV-irradiation, the weak fluorescence and fluorescence fat, such as red and purple is indicative of weak fluorescence. Polychromatic light transmission with a microscope. Tourmaline anion powder with the thermoelectric and piezoelectric components. Changes in temperature and pressure conditions.