Geological processes have occasionally deposited sands that are composed of almost 100% quartz grains. These deposits have been identified and produced as sources of high-purity silica sand. These sands are used in the glassmaking industry. Quartz sand is used in the production of container glass, flat plate glass, specialty glass, and fiberglass.
Quartz glass sand: High-purity quartz sandstone suitable for the manufacture of high-quality glass. “Glass sand” is a sandstone that is composed almost entirely of quartz grains. Pictured here is a specimen of the Oriskany Sandstone from Hancock, West Virginia. In a few locations, the Oriskany is over 99% pure quartz. Much of it has been used for container glass, but some of it has been selected for use in making lenses for the largest telescopes. Specimen is about four inches (ten centimeters across).Quartz flint arrowheads: One of the first uses of quartz, in the form of flint, was the production of sharp objects such as knife blades, scrapers, and projectile points such as the arrowheads shown above.Quartz glass windows: Glassmaking is one of the primary uses of quartz. Image copyright iStockphoto / Chinaface.
