Editing Silicon (section)

===Compounds===
Most silicon is used industrially without being purified, often with comparatively little processing from its natural form. More than 90% of the Earth's crust is composed of [[silicate minerals]], which are compounds of silicon and oxygen, often with metallic ions when negatively charged silicate anions require cations to balance the charge. Many of these have direct commercial uses, such as clays, [[silica]] sand, and most kinds of building stone. Thus, the vast majority of uses for silicon are as structural compounds, either as the silicate minerals or silica (crude silicon dioxide). Silicates are used in making [[Portland cement]] (made mostly of calcium silicates) which is used in [[mortar (masonry)|building mortar]] and modern [[stucco]], but more importantly, combined with silica sand, and gravel (usually containing silicate minerals such as granite), to make the [[concrete]] that is the basis of most of the very largest industrial building projects of the modern world.{{sfn|Greenwood|Earnshaw|1997|p=356}}

Silica is used to make [[fire brick]], a type of ceramic. Silicate minerals are also in whiteware [[ceramic]]s, an important class of products usually containing various types of fired [[clay]] minerals (natural aluminium phyllosilicates). An example is [[porcelain]], which is based on the silicate mineral [[kaolinite]]. Traditional [[glass]] (silica-based [[soda–lime glass]]) also functions in many of the same ways, and also is used for windows and containers. In addition, specialty silica based [[glass fiber]]s are used for [[optical fiber]], as well as to produce [[fiberglass]] for structural support and [[glass wool]] for [[thermal insulation]].

Silicones often are used in [[waterproofing]] treatments, [[molding (process)|molding]] compounds, mold-[[release agent]]s, mechanical seals, high temperature [[lubricant|greases]] and waxes, and [[caulking]] compounds. Silicone is also sometimes used in [[breast implant]]s, contact lenses, [[explosive]]s and [[pyrotechnics]].<ref>{{cite journal |doi=10.1002/prep.200700021 |title=Special Materials in Pyrotechnics: VI. Silicon – An Old Fuel with New Perspectives |last1=Koch |first1=E.C. |last2=Clement |first2=D. |journal=Propellants, Explosives, Pyrotechnics |volume=32 |pages=205–212 |date=2007 |issue=3}}</ref> [[Silly Putty]] was originally made by adding [[boric acid]] to [[silicone oil]].<ref>{{cite book|chapter-url ={{google books |plainurl=y |id=jftapGDTmYUC|page=90}} |chapter=Silly Putty |title=Timeless toys: classic toys and the playmakers who created them |first=Tim |last=Walsh |publisher=Andrews McMeel Publishing |date=2005 |isbn=978-0-7407-5571-2}}</ref><!--Now name-brand Silly Putty also contains significant amounts of elemental silicon. (Silicon binds to the silicone and allows the material to bounce 20% higher.){{Citation needed|date=January 2008}} https://books.google.com/books?id=F2ApK7QnbPUC&pg=PA125 does not mention silicon--> Other silicon compounds function as high-technology abrasives and new high-strength ceramics based upon [[silicon carbide]]. Silicon is a component of some [[superalloy]]s.