Tourmaline (20mesh-325mesh)

Tourmaline is a silicate mineral, the process known as "Bi Yuxi," C list of the medium and gemstones. Tourmaline crystal structure and morphology of the trigonal system. Minute three types of single crystal cone. Columnar crystals. Crystal ends of the crystal face, often appear cylindrical vertical stripes, horizontal surface, terminal spherical triangles. Collectivity was Rod, radial, needle beam, or into dense massive hidden Bulk.
Tourmaline gemstones are normally produced in the rare metal pegmatite containing sodium feldspar, mica lithium, which - TYPE. Tourmaline often with bands, traces of colorless glass sheen, no cleavage. Hardness mare. With brittle. The proportion of 3.03-3.25. 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.