quartz quartz /ˈkwɔrts/

noun

1. () Colorless glass made of almost pure silica  ( crystal , lechatelierite , quartz glass , quartz , vitreous silica )
   colorless glass made of almost pure silica
    The crystal necklace was made of clear quartz, which is said to have healing properties
   The crystal necklace was made of clear quartz, which is said to have healing properties
   
2. 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  ( quartz )
   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 sandy beach sparkled, reflecting the quartz particles mixed in the sand.
   The sandy beach sparkled, reflecting the quartz particles mixed in the sand.