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Tourmaline
 1. Character and structure
Its chemical formula is NaR3Al6〔Si6O18〕(BO3)3(OH)4. It，s called “jasper”.It，s a kind of jewelry.Tourmaline is colourful so it，s enjoyed by people. Its colours can vary with its constitutions.It has the gloss of the glass.Its hardness is 7.0-7.5 and it is brittle. Its specific gravity is 3.03-3.25g/cm3.It has good property of piezoelectricity and pyroelectricity.The tourmaline crystal is like a column. The shape of the tourmaline aggregate is various,such as a stich,needle and so on.
Our factory mainly produces black tourmalines.According to its shape we divide it into crystal(hexahedron)and fiber. 2. The physical-index
| composition |
Al2O3 |
B2O3 |
K2O |
NaO2 |
MgO |
SiO2 |
Fe2O3 |
CaO |
| content（%） |
34.98 |
10.94 |
0.036 |
0.91 |
0.20 |
34.60 |
15.80 |
little |
| remarks |
97.466% |
3. Main use
As tourmaline is unique in piezoelectricity and pyroelectricity,it is widely used in fiber、textile、clothes、painting、purification of water、building materials、household necessities and other composites.The changes of temperature and pressure can cause the potential difference of tourmaline cryatal.The potential difference can ionize and purify the air.
Tourmaline can be also used in the following fields:
(1) As gem materials.
(2) As wall paper、floor board、ceiling、furnitures and concrete.
(3) As packing materials.
(4) As healthy filling materials in the filter tip of cigarettes.
(5) As air-purifying or water-purifying materials.
(6) As additives in the toothpaste or cosmetics.
(7) As anti-biotic painting or coating, used in electrical equipments and household necessities.
(8) As compound pottery and porcelain. |
