Quartz

Crystal system: hexagonal Department 
Chemical composition: SiO2 
Features: separate from the formation of silica minerals, quartz content of the earth's crust is about 12 percent, second only to feldspar-group minerals content. Hardness of 7, the proportion of 2.65, conchoidal fracture, a vulnerability, glass luster, white to colorless, transparent. Containing a variety of metal impurities in a variety of colors when presented with piezoelectric and pyroelectricity. 
Attitude: positive vein, massive, sandy, commonly found in granite, pegmatite, quartz vein or veins of the gangue, but also commonly found in acidic igneous rocks, metamorphic rocks, sedimentary rocks, and often in the hydrothermal veins in the gangue and metal symbiosis. The province was particularly prevalent in the Central Mountain Range east slope into the range of crystallization of quartz veins in schist. 
Uses: crystal glass, optical glass, ceramics, abrasive materials, precious stones or ornaments, refractories, quartz tube, quartz crucible, silicon brick, steel flux Deacidification, desulfurizer, silicon carbide, metal silicon, optical fibers, the manufacture of artificial crystal materials. Electronics industry, such as semiconductor materials, rectifiers, diodes, oscillators and so on.