Editing Glass (section)

== Occurrence in nature ==
{{Main|Volcanic glass|Impactite|Fulgurite}}

Glass can form naturally from volcanic magma. [[Obsidian]] is a common volcanic glass with high silica (SiO<sub>2</sub>) content formed when felsic lava extruded from a volcano cools rapidly.<ref>{{cite web|url=https://geology.com/rocks/obsidian.shtml|title=Obsidian: Igneous Rock – Pictures, Uses, Properties|website=geology.com}}</ref> [[Impactite]] is a form of glass formed by the impact of a [[meteorite]], where [[Moldavite]] (found in central and eastern Europe), and [[Libyan desert glass]] (found in areas in the eastern [[Sahara]], the [[Libyan desert|deserts of eastern Libya]] and [[Western Desert (Egypt)|western Egypt]]) are notable examples.<ref>{{cite web|url=https://geology.com/meteorites/impactites.shtml|title=Impactites: Impact Breccia, Tektites, Moldavites, Shattercones|website=geology.com}}</ref> [[Vitrification]] of [[quartz]] can also occur when [[lightning]] strikes [[sand]], forming hollow, [[dendrite (crystal)|branching rootlike]] structures called [[fulgurite]]s.<ref>{{Cite book|url=https://books.google.com/books?id=cxEEAAAAQAAJ&pg=PA363|title=Land, sea and sky; or, Wonders of life and nature, tr. from the Germ. [Die Erde und ihr organisches Leben] of H.J. Klein and dr. Thomé, by J. Minshull|last=Klein|first=Hermann Joseph|date=1881-01-01}}</ref> [[Trinitite]] is a glassy residue formed from the desert floor sand at the [[Trinity test|Trinity]] [[nuclear testing|nuclear bomb test]] site.<ref>{{Cite news|url=http://www.atlasobscura.com/articles/trinitite-trinity-test-mineral-cultural-jewelry|title=The Long, Weird Half-Life of Trinitite|last=Giaimo|first=Cara|date=2017-06-30|work=Atlas Obscura|access-date=2017-07-08|language=en|df=mdy-all}}</ref> [[Edeowie glass]], found in [[South Australia]], is proposed to originate from [[Pleistocene]] grassland fires, [[lightning]] strikes, or [[hypervelocity impact]] by one or several [[asteroid]]s or [[comet]]s.<ref>{{cite journal|last1=Roperch |first1=Pierrick |last2=Gattacceca |first2=Jérôme |last3=Valenzuela |first3=Millarca |last4=Devouard |first4=Bertrand |last5=Lorand |first5=Jean-Pierre |last6=Arriagada |first6=Cesar |last7=Rochette |first7=Pierre |last8=Latorre |first8=Claudio |last9=Beck |first9=Pierre |title=Surface vitrification caused by natural fires in Late Pleistocene wetlands of the Atacama Desert|journal=Earth and Planetary Science Letters |volume=469 |issue=1 July 2017 |pages=15–26 |date=2017 |doi=10.1016/j.epsl.2017.04.009|bibcode=2017E&PSL.469...15R |s2cid=55581133 |url=https://hal.archives-ouvertes.fr/hal-02889687 }}</ref>

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File:Lipari-Obsidienne (5).jpg|A piece of volcanic [[obsidian]] glass
File:Moldavite Besednice.jpg|[[Moldavite]], a natural glass formed by [[meteorite]] impact, from [[Besednice]], [[Bohemia proper|Bohemia]]
File:Fulgurites-algeria.jpg|Tube [[fulgurites]]
File:Trinitite from Trinity Site.jpg|[[Trinitite]], a glass made by the [[Trinity (nuclear test)|Trinity nuclear-weapon test]]
File:Libyan Desert Glass.jpg|[[Libyan desert glass]]
</gallery>