|1.||a colourless mineral often tinted by impurities, found in igneous, sedimentary, and metamorphic rocks. It is used in the manufacture of glass, abrasives, and cement, and also as a gemstone; the violet-purple variety is amethyst, the brown variety is cairngorm, the yellow variety is citrine, and the pink variety is rose quartz. Composition: silicon dioxide. Formula: SiO2. Crystal structure: hexagonal|
|2.||short for quartz glass|
|[C18: from German Quarz, of Slavic origin]|
A very hard crystalline form of silicon dioxide used in chemical apparatus and in optical and electric instruments.
|quartz (kwôrts) Pronunciation Key
A hard, transparent trigonal mineral that, after feldspar, is the most common mineral on the surface of the Earth. It occurs as a component of igneous, metamorphic, and sedimentary rocks as well as in a variety of other forms such as rock crystal, flint, and agate. Some crystalline forms, such as amethyst, are considered gemstones. Chemical formula: SiO2.