Quartz is a chemical compound consisting of one part silicon and two parts oxygen. It is silicon dioxide (SiO2). It is the most abundant mineral found at Earth's surface, and its unique properties make it one of the most useful natural substances. Quartz is one of the most useful natural materials. Its usefulness can be linked to its physical and chemical properties. It has a hardness of seven on the Mohs Scale which makes it very durable. It is chemically inert in contact with most substances. It has electrical properties and heat resistance that make it valuable in electronic products. Its luster, color, and diaphaneity make it useful as a gemstone and also in the making of glass. Chemical formula :- SiO2 Application : Different forms are also used as gemstones. Because it is a primary ingredient in sand it is also used to make glass & labware, silica brick, cement, and mortar. Ground quartz is used as an abrasive in stonecutting, sandblasting, and glass grinding. Powdered quartz is used in making porcelain, scouring soaps, sandpaper, and wood fillers.