Editing Resin (section)

== Composition ==
Most plant resins are composed of [[terpene]]s. Specific components are [[alpha-Pinene|alpha-pinene]], [[pinene|beta-pinene]], [[carene|delta-3 carene]], and [[sabinene]], the monocyclic terpenes [[limonene]] and [[terpinolene]], and smaller amounts of the tricyclic [[sesquiterpene]]s, [[longifolene]], [[caryophyllene]], and [[cadinene|delta-cadinene]]. Some resins also contain a high proportion of [[resin acid]]s.  [[Rosin]]s on the other hand are less volatile and consist of diterpenes among other compounds.{{citation needed|date=August 2015}}

=== Examples ===
Examples of plant resins include [[amber]], [[Balm of Gilead]], [[balsam]], [[Canada balsam]], [[copal]] from trees of ''[[Protium (plant)|Protium]] copal'' and ''[[Hymenaea courbaril]]'', [[dammar gum]] from trees of the family [[Dipterocarpaceae]], [[dragon's blood]] from the dragon trees (''[[Dracaena (plant)|Dracaena]]'' species), [[elemi]], [[frankincense]] from ''[[Boswellia sacra]]'', [[galbanum]] from ''[[Ferula gummosa]]'', [[gum guaicum|gum guaiacum]]<!--(the article name is surely a spelling error in this title?) --> from the [[lignum vitae]] trees of the genus ''[[Guaiacum]]'', [[kauri gum]] from trees of ''[[Agathis australis]]'', [[hashish]] (Cannabis resin) from ''[[Cannabis indica]]'', [[labdanum]] from mediterranean species of ''[[Cistus]]'', [[mastic (plant resin)]] from the mastic tree ''[[Pistacia lentiscus]]'', [[myrrh]] from shrubs of ''[[Commiphora]]'', [[sandarac]] resin from ''[[Tetraclinis articulata]]'', the national tree of Malta, [[styrax#uses of resin|styrax]] (a [[Benzoin resin]] from various ''[[Styrax]]'' species) and [[spinifex resin]] from Australian grasses.

[[Amber]] is [[fossil]] resin (also called resinite) from coniferous and other tree species. Copal, kauri gum, dammar and other resins may also be found as subfossil deposits. Subfossil copal can be distinguished from genuine fossil amber because it becomes tacky when a drop of a solvent such as [[acetone]] or [[chloroform]] is placed on it.<ref>David Grimaldi, ''Amber: Window to the Past'', 1996, p 16-20, American Museum of Natural History</ref>
African [[copal]] and the kauri gum of New Zealand are also procured in a semi-fossil condition.

=== Rosin ===
{{see also|Rosin}}
[[File:Araucaria Resin.JPG|thumb|right|Extremely [[Viscosity|viscous]] resin extruding from the trunk of a mature ''[[Araucaria columnaris]]''.]]

[[Rosin]] is a solidified resin from which the [[Volatility (chemistry)|volatile]] [[terpene]]s have been removed by distillation. Typical rosin is a transparent or translucent mass, with a vitreous fracture and a faintly yellow or brown colour, non-odorous or having only a slight turpentine odour and taste. Rosin is insoluble in water, mostly soluble in alcohol, [[essential oil]]s, [[diethyl ether|ether]], and hot fatty oils.  Rosin softens and melts when heated and burns with a bright but smoky flame.

Rosin consists of a complex mixture of different substances including organic acids named the [[resin acid]]s. Related to the terpenes, resin acid is [[oxidation|oxidized]] terpenes. Resin acids dissolve in [[alkali]]s to form [[resin soap]]s, from which the resin acids are regenerated upon treatment with acids. Examples of resin acids are [[abietic acid]] (sylvic acid), C<sub>20</sub>H<sub>30</sub>O<sub>2</sub>, [[plicatic acid]] contained in cedar, and [[pimaric acid]], C<sub>20</sub>H<sub>30</sub>O<sub>2</sub>, a constituent of [[galipot]] resin. Abietic acid can also be extracted from rosin by means of hot alcohol. 

Rosin is obtained from [[pine]]s and some other [[plant]]s, mostly [[Pinophyta|conifers]].<ref name=Ullmann>{{cite encyclopedia|doi=10.1002/14356007.a23_073 |chapter=Resins, Natural |encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry |year=2000 |last1=Fiebach |first1=Klemens |last2=Grimm |first2=Dieter |isbn=978-3-527-30673-2|publisher=Wiley-VCH|location=Weinheim}}</ref> Plant resins are generally produced as stem secretions, but in some Central and South American species of ''[[Dalechampia]]'' and ''[[Clusia]]'' they are produced as pollination rewards, and used by some [[stingless bee]] species in nest construction.<ref>{{cite journal | first1=V. | last1=Bittrich | first2= Maria C. E. | last2= Amaral | year=1996 | title=Flower morphology and pollination biology of some Clusia species from the Gran Sabana (Venezuela) | journal=Kew Bulletin | volume=51 | issue=4 | pages=681–694 | doi=10.2307/4119722| jstor=4119722 | bibcode=1996KewBu..51..681B }}</ref><ref>{{cite journal | first=Silmary de Jesus | last= Gonçalves-Alvim |year=2001 | title=Resin-collecting bees (Apidae) on Clusia palmicida (Clusiaceae) in a riparian forest in Brazil | journal=Journal of Tropical Ecology | volume=17 | issue=1 | pages=149–153 | doi=10.1017/s0266467401001092| s2cid= 85842020 }}</ref> [[Propolis]], consisting largely of resins collected from plants such as [[poplars]] and [[conifer]]s, is used by [[honey bee]]s to seal small gaps in their hives, while larger gaps are filled with beeswax.<ref name=Finstrom>{{cite journal|last1=Simone-Finstrom|first1=M.|last2=Spivak|first2=M.|year=2010|title=Propolis and bee health: The natural history and significance of resin use by honey bees|journal=Apidologie|volume=41|issue=3|pages=295–311|doi=10.1051/apido/2010016|s2cid=15828725|url=https://link.springer.com/content/pdf/10.1051/apido/2010016.pdf|doi-access=free}}</ref>

===Petroleum- and insect-derived resins===
[[Shellac]] is an example of an insect-derived resin.

[[Asphaltite]] and Utah resin are petroleum [[bitumen]]s.