Editing Chondrite (section)

{{Short description|Class of stony meteorites made of round grains}}
{{hatnote group|
{{For|trace fossil ichnogenus|Chondrites (genus)}}
{{Distinguish|Chondrodite}}
}}
{{Use dmy dates|date=August 2022}}
{{Infobox meteorite subdivision
|Subdivision               = Type
|Name                      = Chondrite
|Alternative_names         = 
|Image                     = NWA869Meteorite.jpg
|Image_caption             = A specimen of the NWA 869 chondrite (type L4–6), showing [[chondrule]]s and metal flakes
|Image_alt_text            = 
|Compositional_type        = Stony
|Structural_classification = 
|Parent_body               = Small to medium asteroids that were never part of a body large enough to undergo melting and planetary differentiation.
|Composition               = 
|Petrologic_type           = 3–6
|Number_of_specimens       = Over 27,000
|TKW                       = <!-- {{Convert||kg}} -->
|Image2                    = 
|Image2_caption            = 
|Image2_alt_text           = 
}}

A '''chondrite''' {{IPAc-en|'|k|Q|n|d|r|ai|t}} is a stony (non-[[metal]]lic) [[meteorite]] that has not been modified by either [[melting]] or [[planetary differentiation|differentiation]] of the [[parent body]].{{efn|The use of the term non-metallic does not imply the total absence of metals.}}<ref>{{cite web |url=http://www.ucm.es/info/planetas/programa/tema2/2.2.htm |title=2.2 La composición de la Tierra: el modelo condrítico in Planetología. Universidad Complutense de Madrid |access-date=19 May 2012 |archive-date=15 June 2009 |archive-url=https://web.archive.org/web/20090615115240/http://www.ucm.es/info/planetas/programa/tema2/2.2.htm |url-status=live }}</ref> They are formed when various types of dust and small grains in the early [[Solar System]] accreted to form primitive [[asteroid]]s. Some such bodies that are captured in the planet's [[gravity well]] become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7%<ref name="meteoroide">{{cite web
|url = http://www.solarviews.com/span/meteor.htm
|title = Meteoroides y Meteoritos
|access-date = 2009-04-18
|author = Calvin J. Hamilton (Translated from English by Antonio Bello)
|language = es
|archive-date = 25 February 2021
|archive-url = https://web.archive.org/web/20210225014338/https://solarviews.com/span/meteor.htm
|url-status = live
}}</ref> and 86.2%.<ref>{{cite journal |title=Meteorites for the Sahara: Find locations, shock classification, degree of weathering and pairing |journal=Meteoritics |issn=0026-1114 |volume=30 |issue=1 |pages=113–122 |bibcode=1995Metic..30..113B |last1=Bischoff |first1=A. |last2=Geiger |first2=T. |year=1995 |doi=10.1111/j.1945-5100.1995.tb01219.x|doi-access=free }}</ref>

Their study provides important clues for understanding the origin and age of the Solar System, the synthesis of [[organic compound]]s, the [[Abiogenesis|origin of life]] and the presence of water on [[Earth]]. One of their characteristics is the presence of [[chondrule]]s (from the [[Ancient Greek]] χόνδρος ''chondros'', grain), which are round grains formed in space as [[molten]] or partially molten droplets of distinct minerals. Chondrules typically constitute between 20% and 80% of a chondrite by volume.<ref name="condru">{{cite web
|url = http://axxon.com.ar/not/186/c-1861106.htm
|title = Pistas químicas apuntan a un origen de polvo para los planetas terrestres
|access-date = 11 May 2009
|author = Axxón
|language = es
|archive-date = 3 August 2008
|archive-url = https://web.archive.org/web/20080803015710/http://axxon.com.ar/not/186/c-1861106.htm
|url-status = live
}}</ref>

Chondrites can be distinguished from [[iron meteorite]]s by their low iron and nickel content. Non-metallic meteorites that lack chondrules are [[achondrite]]s, which are believed to have formed more recently than chondrites.<ref name="book">{{cite book
| author = Jordi, Llorca Pique
| publisher = Universitat Jaume I
| title = El sistema solar: Nuestro pequeño rincón en la vía láctea
| year = 2004
| isbn = 978-8480214667
| pages = 75
| chapter = Nuestra historia en los meteoritos
| chapter-url = https://books.google.com/books?id=27VVdmdHv3gC&q=meteoritos+met%C3%A1licos&pg=PT38
| access-date = 30 October 2020
| archive-date = 13 January 2023
| archive-url = https://web.archive.org/web/20230113183918/https://books.google.com/books?id=27VVdmdHv3gC&q=meteoritos+met%C3%A1licos&pg=PT38
| url-status = live
}}</ref> There are currently over 27,000 chondrites in the world's collections. The largest individual stone ever recovered, weighing 1770&nbsp;kg, was part of the [[Meteorite fall|Jilin]] meteorite shower of 1976. Chondrite falls range from single stones to extraordinary showers consisting of thousands of individual stones. An instance of the latter occurred in the [[Holbrook (meteorite)#Holbrook meteorite|Holbrook fall]] of 1912, in which an estimated 14,000 stones were grounded in northern [[Arizona]].