Quartz sand is a hard, wear-resistant, chemically stable silicate mineral, and its main mineral component is SiO2. The color of quartz sand is various, usually milky white, colorless, gray. Hardness 7, brittle, no cleavage, shell-like fracture. Grease luster, density 2.65g/cm3, its chemical, thermal and mechanical properties have obvious anisotropy. Insoluble in acid, slightly soluble in KOH solution, melting point 1750°C. With piezoelectricity.