quartz

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.Examples: "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."; "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."; "My meat eats me. Who waits at the gate? / Mother of quartz, your words writhe into my ear. / Renew the light, lewd whisper."countableuncountable

2. (uncountable, slang) Crystal meth: methamphetamine hydrochloride.slanguncountable