Tourmaline is the general name of tourmaline minerals, and its chemical composition is complex. It is a cyclic silicate mineral of aluminum, sodium, iron, magnesium and lithium, characterized by boron. The hardness of tourmaline is usually 7~7.5, and the density varies slightly according to different kinds. Tourmaline is also called tourmaline and tourmaline.
Tourmaline has unique properties such as piezoelectricity, pyroelectricity, conductivity, far infrared radiation and negative ion release. It can be compounded with other materials by physical or chemical methods to make a variety of functional materials, which are used in environmental protection, electronics, medicine, chemical industry, light industry, building materials and other fields.