Quartz (silicon dioxide) Collection of the Everhart Museum Quartz is the most common mineral on the earth’s crust and the most varied in terms of color and form, with well over 100 distinctive types. The most common appearance of quartz is clear or milky white, but purple, brown, pink and gray are also frequent occurrences. Quartz has a variety of uses in glass, electrical components, optical lenses, construction, ornamentation, and a number of other industrial uses. However, because natural quartz crystals are very often twinned, or inter-grown with each other, most quartz used for industrial purposes is synthesized.

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