Tourmaline is not only a popular colorful gemstone but also a kind of environmental mineral. This paper deals with the spontaneous polarization of tourmaline, which is responsible for such characteristics of tourmaline as surface electric field, electrolysis of water molecules, and release of negative air ions, thus making this mineral good for the environment in such aspects as absorbing heavy metal ions and degrading organic great molecular pollutants in water. When people wear tourmaline jewelry, its spontaneous polarization phenomenon is also helpful to body protection in that it has certain electromagnetic shielding effect and can promote metabolism of the human body.