A very hard mineral composed of silica, SiO2, found worldwide in many different types of rocks, including sandstone and granite. Varieties of quartz include agate, chalcedony, chert, flint, opal, and rock crystal.
Origin: German Quarz, from Middle High German quarc, of Slavic origin.
The graphics subsystem in the Mac OS X operating system. It provides two-dimensional drawing and windowing, and its rendering engine is based on the Adobe PDF model. See Mac OS X. See also quartz crystal.
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.