A hard mineral consisting of silica, found widely in igneous and metamorphic rocks and typically occurring as colourless or white hexagonal prisms. It is often coloured by impurities (as in amethyst, citrine, and cairngorm).
More example sentences
- The sample is strongly foliated and consists of garnet, biotite, quartz, plagioclase and cordierite.
- Because they formed within the peat, coal balls generally contain very little detrital clay minerals and quartz.
- Adjacent to the gray quartz with acanthite and gold is sugary white quartz with massive galena.
mid 18th century: from German Quarz, from Polish dialect kwardy, corresponding to Czech tvrdý 'hard'.
Definition of quartz in:
- The US English dictionary