● About Tourmaline
  A complex silicate of boron and aluminum, calling"imperial seal" of the gems in China, whose composition varies widely because of substitutions. Tourmaline appear various colors ,for example black (schorl), blue (indicolite), pink and red (rubellite), brown (dravite), green, multicolored, rarely white; vitreous; streak white. Hexagonal, usually short to long prismatic crystals that commonly have a rounded triangular cross section, striated lengthwise; also radiating, columnar, compact..
   Tourmaline is natural mineral of many elements ,its chemical compositions are: Boron( B), magnesium(Mg), aluminium( Al), silicate, its chemical formula is: (Na,Ca)(Mg,Fe)3B3Al6Si6(O, Whether OH,F) 31 and a-SiO2 contain V not micro- of, Cr, Zr, Mn, Ti, and elements helpful to the human body, such as Sr, Ga2O3,etc.. The hardness of tourmaline is generally about 7.3-7.6, the relative density is 3.03-3.25.    Tourmaline has inexistent physics and chemistry characteristics that other minerals own, for instance: piezoelectricity, thermo-electricity,, anion and far infrared, etc..
● Specifications
   Our company choose high-quality ore as material to process tourmaline grain and powder, the products are exported to Japan and Korea, Taiwan etc. countries and areas. We mainly provide tourmaline products as follows:
A: Black tourmaline crystal and fibre ore
B: Black tourmaline powder
C: Black crystal tourmaline for craft
D: Pink tourmaline ore and powder
● Chemical analysis of black tourmaline