1. A hard glossy mineral consisting of silicon dioxide in crystal form; present in most rocks (especially sandstone and granite); yellow sand is quartz with iron oxide impurities
   "The geologist identified quartz crystals in the rock sample"
    
2. Colourless glass made of almost pure silica
   "Quartz glass is often used in high-temperature laboratory equipment due to its low thermal expansion";
   - quartz glass, vitreous silica, lechatelierite, crystal

Sounds like: courts, quarts

Derived forms: quartzes

Type of: mineral, natural glass

Encyclopedia: Quartz