Knowra Silicon dioxide Silicon dioxide Silicon dioxide (SiO₂) is a compound of silicon and oxygen. It occurs in crystalline forms such as quartz and in noncrystalline forms such as silica glass.
Silicon–oxygen tetrahedron : A structural unit with one silicon atom surrounded by four oxygen atoms in a tetrahedral arrangement. These units link together to form the extended structures of most silica minerals and glasses.
Glass : An inorganic solid whose atoms lack the long-range order of a crystal. Silicon dioxide is the main ingredient in many common glasses.
Silicate minerals : Minerals built primarily from silicon–oxygen units, often combined with metal cations. Silicon dioxide is the simplest end-member composition within the broader silicate family.
Silicosis : A progressive lung disease caused by inhaling respirable crystalline silica particles. Cutting, mining, and grinding silica-bearing materials can release the particles that cause it.
Silica polymorphs : Distinct crystalline structures that share the chemical composition SiO₂. Quartz, cristobalite, and tridymite differ in how their silicon–oxygen units are arranged.
Fused silica : High-purity, noncrystalline silicon dioxide produced by melting or flame-fusing silica. Its low thermal expansion and optical clarity suit demanding laboratory and optical uses.
Silica cycle : The movement of dissolved and particulate silicon through rocks, water, organisms, and sediments. Weathering and biological uptake continually move silicon dioxide into and out of Earth’s surface reservoirs.
Quartz weathering : The physical and chemical breakdown of quartz-bearing rocks at Earth’s surface. Quartz’s durability helps it persist as grains in soils and sediments.
Quartz : A crystalline mineral composed of silicon dioxide, common in rocks and sediments. It is the best-known natural crystalline form of silicon dioxide.
Silicon dioxide in semiconductor devices : A thin silica layer used as an insulator and interface material in semiconductor structures. Its electrical insulation made it central to traditional silicon-based transistors.
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