Quartz

Quartz, widely distributed mineral of many varieties that consists primarily of silica, or silicon dioxide (SiO2). Large amounts of quartz sand (also known as silica sand) are used in the manufacture of glass and ceramics and for foundry molds in metal casting. Crushed quartz is used as an abrasive in sandpaper, silica sand is employed in sandblasting, and sandstone is still used whole to make whetstones, millstones, and grindstones. Silica glass (also called fused quartz) is used in optics to transmit ultraviolet light. Tubing and various vessels of fused quartz have important laboratory applications, and quartz fibers are employed in extremely sensitive weighing devices. Because of its piezoelectric property, a quartz plate can be used as a pressure gauge, as in depth-sounding apparatus. Quartz is very resistant to both chemicals and heat. It is therefore often used as foundry sand. With a melting temperature higher than most metals, it can be used for the molds and cores of common foundry work. Refractory bricks are often made of quartz sand because of its high heat resistance. Quartz sand has a high resistance to being crushed. In the petroleum industry, sand slurries are forced down oil and gas wells under very high pressures in a process known as hydraulic fracturing. The open fractures facilitate the flow of natural gas into the well bore. Quartz crystals are used to make oscillators for watches, clocks, radios, televisions, electronic games, computers, cell phones, electronic meters, and GPS equipment. Quartz makes an excellent gemstone. Based on the application and customer requirement, quartz can be supplied in specified size. The three main variants are quartz powder, quartz lumps and quartz grits.