Editing Metalloid (section)

===Glass formation===
[[File:Fibreoptic4.jpg|thumb|right|[[Optical fibers]], usually made of pure [[silicon dioxide]] glass, with additives such as [[boron trioxide]] or [[germanium dioxide]] for increased sensitivity|alt=A bunch of pale yellow semi-transparent thin strands, with bright points of white light at their tips.]]
The oxides [[boron trioxide|B<sub>2</sub>O<sub>3</sub>]], [[silicon dioxide|SiO<sub>2</sub>]], [[germanium dioxide|GeO<sub>2</sub>]], [[arsenic trioxide|As<sub>2</sub>O<sub>3</sub>]], and [[antimony trioxide|Sb<sub>2</sub>O<sub>3</sub>]] readily form [[glass]]es. [[Tellurium dioxide|TeO<sub>2</sub>]] forms a glass but this requires a "heroic quench rate"<ref name=K2002/> or the addition of an impurity; otherwise the crystalline form results.<ref name=K2002>[[#Kaminow2002|Kaminow & Li 2002, p.&nbsp;118]]</ref> These compounds are used in chemical, domestic, and industrial glassware<ref>[[#Deming1925|Deming 1925]], pp.&nbsp;330 (As<sub>2</sub>O<sub>3</sub>), 418 (B<sub>2</sub>O<sub>3</sub>; SiO<sub>2</sub>; Sb<sub>2</sub>O<sub>3</sub>); [[#Witt1968|Witt & Gatos 1968, p.&nbsp;242]] (GeO<sub>2</sub>)</ref> and optics.<ref>[[#Eagleson1994|Eagleson 1994, p.&nbsp;421]] (GeO<sub>2</sub>); [[#Rothenberg1976|Rothenberg 1976, 56, 118–19]] (TeO<sub>2</sub>)</ref> Boron trioxide is used as a [[glass fibre]] additive,<ref>[[#Geckeler1987|Geckeler 1987, p.&nbsp;20]]</ref> and is also a component of [[borosilicate glass]], widely used for laboratory glassware and domestic ovenware for its low thermal expansion.<ref>[[#Kreith2005|Kreith & Goswami 2005, pp.&nbsp;12–109]]</ref> Most ordinary glassware is made from silicon dioxide.<ref>[[#Russell2005|Russell & Lee 2005, p.&nbsp;397]]</ref> Germanium dioxide is used as a glass fibre additive, as well as in infrared optical systems.<ref>[[#Butterman2005|Butterman & Jorgenson 2005, pp.&nbsp;9–10]]</ref> Arsenic trioxide is used in the glass industry as a [[glass coloring and color marking|decolourizing]] and fining agent (for the removal of bubbles),<ref>[[#Shelby|Shelby 2005, p.&nbsp;43]]</ref> as is antimony trioxide.<ref>[[#Butterman2004|Butterman & Carlin 2004, p.&nbsp;22]]; [[#Russell2005|Russell & Lee 2005, p.&nbsp;422]]</ref> Tellurium dioxide finds application in laser and [[nonlinear optics]].<ref>[[#Träger2007|Träger 2007, pp.&nbsp;438, 958]]; [[#Eranna2011|Eranna 2011, p.&nbsp;98]]</ref>

[[Amorphous]] [[metallic glass]]es are generally most easily prepared if one of the components is a metalloid or "near metalloid" such as boron, carbon, silicon, phosphorus or germanium.<ref>[[#Rao2002|Rao 2002, p.&nbsp;552]]; [[#Loffler|Löffler, Kündig & Dalla Torre 2007, p.&nbsp;17–11]]</ref>{{refn|1=Research published in 2012 suggests that metal-metalloid glasses can be characterised by an interconnected atomic packing scheme in which metallic and [[covalent]] bonding structures coexist.<ref>[[#Guan|Guan et al. 2012]]; [[#World|WPI-AIM 2012]]</ref>|group=n}} Aside from thin films deposited at very low temperatures, the first known metallic glass was an alloy of composition Au<sub>75</sub>Si<sub>25</sub> reported in 1960.<ref>[[#Klement|Klement, Willens & Duwez 1960]]; [[#Wanga|Wanga, Dongb & Shek 2004, p.&nbsp;45]]</ref> A metallic glass having a strength and toughness not previously seen, of composition Pd<sub>82.5</sub>P<sub>6</sub>Si<sub>9.5</sub>Ge<sub>2</sub>, was reported in 2011.<ref>[[#Demetriou|Demetriou et al. 2011]]; [[#Oliwenstein|Oliwenstein 2011]]</ref>

Phosphorus, selenium, and lead, which are less often recognised as metalloids, are also used in glasses. [[Phosphate glass]] has a substrate of phosphorus pentoxide (P<sub>2</sub>O<sub>5</sub>), rather than the silica (SiO<sub>2</sub>) of conventional silicate glasses. It is used, for example, to make [[sodium lamp]]s.<ref>[[#Karabulut|Karabulut et al. 2001, p.&nbsp;15]]; [[#Haynes|Haynes 2012, pp.&nbsp;4–26]]</ref> Selenium compounds can be used both as decolourising agents and to add a red colour to glass.<ref>[[#Schwartz2002|Schwartz 2002, pp.&nbsp;679–80]]</ref> Decorative glassware made of traditional [[lead glass]] contains at least 30% [[lead(II) oxide]] (PbO); lead glass used for radiation shielding may have up to 65% PbO.<ref>[[#Carter|Carter & Norton 2013, p.&nbsp;403]]</ref> Lead-based glasses have also been extensively used in electronic components, enamelling, sealing and glazing materials, and solar cells. Bismuth based oxide glasses have emerged as a less toxic replacement for lead in many of these applications.<ref>[[#Maeder|Maeder 2013, pp.&nbsp;3, 9–11]]</ref>