The BIXI, which mineral name tourmaline, it contains the most abundant color comparing with all other gems .Its color has various ones, such as, red , yellow , blue , green , purple , brown , black and excessive between two kinds of colors, for instance pink, the more special one is often many kinds of colors on the same kind of crystal, called the multicolor tourmaline.
The Bixi’s chemical formula is very complex which be written as (Na , Ca) (Mg , Fe2 +, Fe3+,Li,Al)3AL6[Si6O18](Bo3)3(OH; F)4. Its crystal belongs to the three sides crystal which mostly show short column , long column or needle column form , the both end has different conical surfaces, section take the form of spherical trigonometry, crystal except that black, colourless and opaque , generally can see dichroism obviously. The cylinder is long usually including much more element Fe and Mg, taking the form of tripartite column with element Mg, the crystal is crassitude; The lithium tourmaline often takes the form of needle.
The producing area of Bixi is mainly, Brazil , U.S.A. , Burma , Sri Lanka , China (Xinjiang , the Inner Mongol , Yunnan ). Now there are pink tourmaline, Verdelite, Brown tourmaline, Rubelite, Yellow tourmaline, Schor., appearing in the market commonly.