Definition of "quartz"

quartz

/k(w)ɔːts/

noun
countable and uncountable, plural quartzes
1. (mineralogy) The most abundant mineral on the earth's surface, of chemical composition silicon dioxide, SiO2. It occurs in a variety of forms, both crystalline and amorphous. Found in every environment.
  Quotations
  The telescope and collimator have each an object-glass consisting of a single lens of quartz 1½ inch diameter and a focal length of 18½ inches for the sodium yellow light, but not more than 16 inches for the highest rays measured.
  1883, George Downing Liveing, James Dewar, “On the Ultra-Violet Spectra of the Elements”, in Philosophical Transactions of the Royal Society, volume 174, Barrison and Sons, part I, page 188
  Subsequently, the old Malay brought him the present specimen in a state of torpidity, telling him he had found it in a cavity of the quartz reef.
  1892 April, Armiger Barczinsky, “The Golden Snail”, in Sylvanus Urban (pseudonym of Edward Cave), editor, The Gentleman's Magazine, volume 272, page 331
  My meat eats me. Who waits at the gate? / Mother of quartz, your words writhe into my ear. / Renew the light, lewd whisper.
  1948, Theodore Roethke, “The Shape of the Fire”, in The Lost Son and Other Poems
2. (uncountable, slang) Crystal meth: methamphetamine hydrochloride.