Fulgurites (from the Latin "fulgur" meaning thunderbolt) are natural hollow carrot-shaped glass tubes formed in quartzose sand or soil by lightning strikes. Fulgurites can also be produced when a high voltage electrical distribution network breaks and the lines fall onto a conductive surface with sand beneath. They are sometimes referred to as "petrified lightning." The glass formed is called lechatelierite which may also be formed by meteorite impact and volcanic explosions. As it is amorphous it is classified as a mineraloid.

The tubes can be up to a couple of centimeters in diameter, and meters long. Their color varies depending on the composition of the sand they formed in, ranging from black or tan to green or a translucent white. The interior is normally very smooth or lined with fine bubbles; the exterior is generally coated with rough sand particles. They are rootlike in appearance and often show branching or small holes. Fulgurites occasionally form as glazing on solid rocks (sometimes referred to as an "exogenic fulgurite" [ [http://findarticles.com/p/articles/mi_m0GDX/is_5_79/ai_n6248984/pg_1 Exogenic fulgurites from Elko County, Nevada: a new class of fulgurite associated with large soil-gravel fulgurite tubes] ("Rocks & Minerals", Sep/Oct 2004, Vol. 79, No. 5.)] ).

Fulgurites are a very rare phenomenon. A very large one was found in South Amboy, New Jersey. This was roughly nine feet long with a diameter of three inches (7.6 cm) near the surface of the ground, and tapered to roughly three sixteenths of an inch (5 mm) in diameter at the deepest point recovered. As is often the case due to the fragile nature of fulgurites, scientists were unable to extract it in one piece and the largest recovered fragment was a mere six inches (15.2 cm) long. Fulgurites are notably found high on Mount Thielsen ("the lightning rod of the Cascade Range") where they form a brownish-green glaze on rocks (especially on the final five or ten feet of the summit pinnacle) and on the shores of the Great Lakes.

The largest fulgurite known is at the Peabody Museum of Natural History at Yale University, which has on display a 13-foot (4 m) long fulgurite from the shores of Lake Congamond in northern Connecticut. The fulgurite has been on display at the Museum since the 1950s, and is viewable in the new Hall of Minerals, Earth and Space as of May, 2006. A specimen of fulgurite over 3 metres long is in the Natural History Museum in London. It is preserved in sections of over 50cm. Another museum speciment is on display in Philadelphia, USA, at the Academy of Natural Sciences; it was discovered in 1940.


External links

* [http://environment.newscientist.com/channel/earth/mg19426102.100-the-word-fulgurite.html Fulgurites in New Scientist]
* [http://amsglossary.allenpress.com/glossary/browse?s=f&p=51 Glossary of Meteorology definitions (including Fulgurite).]
* [http://ira.usf.edu/CAM/exhibitions/1998_12_McCollum/supplemental_didactics/47.Petrified.pdf Petrified Lightning by Peter E. Viemeister (pdf)]
* [http://www.mindat.org/min-7747.html Mindat with location data]
* [http://www.minsocam.org/MSA/collectors_corner/arc/njfulgurite.htm W. M. Myers and Albert B. Peck, "A Fulgurite from South Amboy, New Jersey,"] American Mineralogist, Volume 10, pages 152-155, 1925
* [http://plaza.ufl.edu/rakov/Gas.html Vladimir A. Rakov, "Lightning Makes Glass,"] 29th Annual Conference of the Glass Art Society, Tampa, Florida, 1999

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Look at other dictionaries:

  • fulgurite — ● fulgurite nom féminin (latin fulgur, uris, foudre) Portion d un sable, limon ou sol siliceux, qui a été fondue par la foudre, puis qui s est consolidée. ⇒FULGURITE, subst. fém. Portion de sable, limon ou sol siliceux, qui a été fondue par la… …   Encyclopédie Universelle

  • Fulgurite — Ful gu*rite, n. [L. fulguritus, p. p. of fulgurire to strike with lightning, fr. fulgur lightning: cf. F. fulgurite.] A vitrified sand tube produced by the striking of lightning on sand; a lightning tube; also, the portion of rock surface fused… …   The Collaborative International Dictionary of English

  • Fulgurite — Fulgurite, die durch Blitzschlag erzeugten Gesteinsabänderungen. [207] Sie bestehen in der Regel in einer Schmelzung und Verglasung der vom Blitz getroffenen Gesteine, und zwar muß die Entwicklung der Temperatur bei der elektrischen Entladung… …   Lexikon der gesamten Technik

  • fulgurite — s. f. 1. Vitrificação produzida na areia pela passagem do raio. 2. Explosivo moderno …   Dicionário da Língua Portuguesa

  • fulgurite — [ful′gyoo rīt΄] n. [L fulgur (see FULGURATE) + ITE1] a glassy substance, usually tube shaped, formed by fusion when sand, rock, etc. are struck by lightning …   English World dictionary

  • Fulgurite — Fulgurit Fulgurite (von lat. fulgur, „Blitz“), auch Blitzverglasung, Blitzsinter, Blitzröhren, sind durch Blitzeinschlag im Gestein entstandene Röhren. Durch die beim Einschlag entstehenden Temperaturen von bis zu 30.000 °C verglasen die… …   Deutsch Wikipedia

  • Fulgurite — Des fulgurites. Les fulgurites (du latin fulgur signifiant foudre) sont les morceaux de verre naturel, généralement en forme de tuyau creux quasi cylindrique, formés par les impacts de foudre dans un matériau siliceux, généralement du sable …   Wikipédia en Français

  • fulgurite — /ful gyeuh ruyt /, n. a tubelike formation in sand or rock, caused by lightning. [1825 35; < L fulgur (see FULGURATE) + ITE1] * * * ▪ mineral       a glassy silica mineral (lechatelierite or amorphous SiO2) fused in the heat from a lightning… …   Universalium

  • fulgurite — noun Etymology: International Scientific Vocabulary, from Latin fulgur Date: 1834 an often tubular vitrified crust produced by the fusion of sand or rock by lightning …   New Collegiate Dictionary

  • FULGURITE — n. m. T. de Physique Tube vitrifié dû à la foudre qui, tombant dans le sable, le fond sur son passage …   Dictionnaire de l'Academie Francaise, 8eme edition (1935)

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