Some types of SiO2 employed for industrial purposes include high-purity α-quartz, vitreous silica, silica gels, and diatomaceous earth. Very pure quartz crystals in oscillators and other electromechanical devices constitute one of the most critical applications of high-grade quartz. Such oscillators are the heart of quartz watches and enable radio stations to remain on an assigned frequency. The fusion of sand and sodium carbonate yields sodium silicate (ranked 46 among the top 50 chemicals produced in the United States), which is converted to silica gel or used to manufacture detergents and cleaning agents. Concentrated aqueous solutions of Na2SiO3 are often sold in hobby shops under the name of water glass. When white sand is fused at 1500 °C with a mixture of sodium and calcium oxides and carbonates, the result is a molten mixture of silicates, Na2SiO3, CaSiO3, and silica. Cooling this liquid produces ordinary soda glass, an amorphous transparent substance that looks like a solid. Variations in the proportions of the three basic starting materials and additions of a few other ingredients will produce a variety of glasses with modified properties. If calcium is replaced with lead, a flint glass with a higher refractive index result; SiO2 partially replaced with P4O10 yields crown glass. Adding boron oxides to soda glass yields a borosilicate glass (Pyrex) with significantly improved thermal-shock properties resulting from the reduced expansion coefficient. If you are looking for high quality, high purity and cost-effective silicon dioxide, or if you require the latest silicon dioxide price, please email contact mis-asia.