Properties and Uses Silica sand, also known as quartz sand, is made up of two main elements - silica and oxygen. Washed Silica Sand makes up around 86% of the earth's crust. When mined, silica sand goes through an extensive washing process to ensure it is pure silicon dioxide (SiO2). This washing process is critical to remove any Fe2O3, Al2O3 and other impurities that may be presen... https://fortunetelleroracle.com/other/washed-silica-sand--essential-for-construction-and-industrial-applications-946975