1. A white or colourless vitreous insoluble solid (SiO₂); various forms occur widely in the earth's crust as quartz or cristobalite or tridymite or lechatelierite
   "silicon dioxide is the main component of sand";
   - silica, silicon oxide

Derived forms: silicon dioxides

Type of: oxide

Part of: cristobalite, crystal, lechatelierite, quartz, quartz glass, quartz sand, tridymite, vitreous silica

Encyclopedia: Silicon dioxide