# Evenkite

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> Source: https://en.wikipedia.org/wiki/Evenkite
> Source revision: 1330969829
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{{Short description|Hydrocarbon mineral}}
{{infobox mineral
| name        = Evenkite
| boxwidth    = 
| boxbgcolor  = 
| image       = Evenkite-444375.jpg
| alt         = 
| caption     = Evenkite from [Dubnik](/source/Dubnik), [Slovakia](/source/Slovakia)
| category    = [Organic mineral](/source/Organic_mineral)
| formula     = C<sub>24</sub>H<sub>50</sub>
| IMAsymbol   = Evk<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| molweight   = 
| strunz      = 10.BA.50
| dana        = 
| system      = [Orthorhombic](/source/Orthorhombic)
| class       = Dipyramidal (mmm) <br/>[H-M symbol](/source/H-M_symbol): (2/m 2/m 2/m)
| symmetry    = ''Pbcm''
| unit cell   = a = 7.47, b = 4.98, c = 65.85&nbsp;[Å]; Z&nbsp;=&nbsp;4
| color       = Colorless or pale yellow
| colour      = 
| habit       = Tabular pseudohexagonal crystals, granular, disseminated
| twinning    = Polysynthetic
| cleavage    = {001} Perfect
| fracture    = 
| tenacity    = 
| mohs        = 1
| luster      = Waxy
| streak      = 
| diaphaneity = Transparent
| gravity     = 0.87
| density     = 
| polish      = 
| opticalprop = Biaxial (+)
| refractive  = n<sub>α</sub> = 1.504 n<sub>β</sub> = 1.504 n<sub>γ</sub> = 1.553
| birefringence = δ = 0.049
| pleochroism = 
| 2V          = 
| dispersion  = 
| extinction  = 
| length fast/slow =
| fluorescence = 
| absorption  = 
| melt        = 
| fusibility  = 
| diagnostic  = 
| solubility  = 
| impurities  = 
| alteration  = 
| other       = 
| prop1       = 
| prop1text   = 
| references  = <ref name=Mindat>[http://www.mindat.org/min-1428.html Mindat.org]</ref><ref name=Webmin>[http://webmineral.com/data/Evenkite.shtml Webmineral data]</ref><ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/evenkite.pdf Handbook of Mineralogy]</ref><ref name=span1998/><ref name=jech2007/><ref name=skrop1953/><ref name=plant2006/><ref name=kote2006/><ref name=pilo2005/>
}}
'''Evenkite''' is a rare [hydrocarbon](/source/hydrocarbon) mineral with formula C<sub>24</sub>H<sub>50</sub>; specifically, H<sub>3</sub>C–(CH<sub>2</sub>)<sub>22</sub>–CH<sub>3</sub>, the [alkane](/source/alkane) ''n''-[tetracosane](/source/tetracosane).<ref name="kote2006" /> It occurs as very soft ([Mohs hardness](/source/Mohs_hardness) 1) transparent crystals, colorless to yellow, with a waxy luster. The softness is a characteristic of crystalline long-chain alkanes, which are the main constituents of [paraffin wax](/source/paraffin_wax).<ref name=pilo2005/>

Evenkite one of very few minerals that consist of crystalline hydrocarbons,<ref name=plant2006/><ref name=jech2007/> which include [carpathite](/source/carpathite) (pure crystalline [coronene](/source/coronene), a [polyaromatic hydrocarbon](/source/polyaromatic_hydrocarbon)).<ref name=echi2007/>  It is also one of the few non-porous minerals that floats on water. It has been claimed to be the same as [hatchettite](/source/hatchettite).<ref name=span2000/>

==History and geologic occurrence==
Evenkite was first described in 1953 by A. V. Shropyshev, as found in the Khavokiperskiye deposit, [Lower Tunguska River](/source/Nizhnyaya_Tunguska), [Evenkiysky District](/source/Evenkiysky_District), [Siberia](/source/Siberia), [Russia](/source/Russia), where it occurs inside [geode](/source/geode)s and [vug](/source/vug)s in a [quartz](/source/quartz) [vein](/source/vein_(geology)) in [welded tuff](/source/welded_tuff).<ref name=skrop1953/> It was named after the district.<ref name=Webmin/>  It has also been reported from the [Hautes-Alpes](/source/Hautes-Alpes) region in France and the [Slanské](/source/Slansk%C3%A9) and [Vihorlat](/source/Vihorlat) mountains of [Slovakia](/source/Slovakia).<ref name=Mindat/>

Evenkite appears as flaky wax partials on top of the quartz crystals.<ref name=span1998/> Associated minerals include quartz, [chalcedony](/source/chalcedony), [pyrite](/source/pyrite), [pyrrhotite](/source/pyrrhotite), [sphalerite](/source/sphalerite), [galena](/source/galena), [chalcopyrite](/source/chalcopyrite) and [calcite](/source/calcite).<ref name=HBM/>

Evenkite was the last part of the geode to form.<ref name=span1998/>  It is believed to have resulted from thermal cracking of the organic matter (mainly marine plants) that where trapped in the [septarian concretion](/source/septarian_concretion)s during the [Jurassic](/source/Jurassic) burial, as the buried sediments were subjected to high pressure and temperatures.<ref name=jech2007/> The [French Alps](/source/French_Alps) region received a lot of geological uplift after the Jurassic burial.<ref name=span1998/>

==See also==

* [Ozokerite](/source/Ozokerite)
* [Mellite](/source/Mellite)

==References==
<references>
<ref name=skrop1953>Skropyshev, A.V. "On Paraffin from a Base Metal Vein". Doklady Acad, 1953, P.717-719.</ref>

<ref name=span1998>Spangenberg, J.E. and Meisser, N. "Geochemistry of the organic mineral evenkite in septarian concretions in the Oxfordian marls of the French Alps". Mineralogical Magazine, 1998, p.1436-1437.</ref>

<ref name=span2000>J. E. Spangenberg and  N. Meisser (2000): ""Hatchettite and Evenkite - two mineral names for the same natural crystalline paraffinic vax[isotope ratio study]". Paper EDB-00:118740 ''Abstracts of the 5th Isotope Workshop of European Society for Isotope Research'', pages 188-191. {{isbn|83-912388-8-1}}</ref>

<ref name=pilo2005>Pilonen, P.C. and Ercit, T.S. "New Mineral Names". American Mineralogist, 2005, p.1466-1469.</ref>

<ref name=plant2006>Platonova, N.V. and Kotel'nikova, E.N. "Synthesis of Organic Mineral Evenkite". Geology of Ore Deposits, 2006, p.87-91.</ref>

<ref name=kote2006>Kotel'nikova, E.N., Platonova, N.V., and Filatov, G.M. "Identification of Biogenic Paraffins and Their Thermal Phase Transitions". Geology of Ore Deposits, 2006, p.607-709.</ref>

<ref name=jech2007>Jechlicka, J., Villar, S., and Edwards, G.M. "Raman spectroscopy of natural accumulated paraffins from rocks: Evenkite, ozokerite, and hatchtine". Spectrochimica Act, 2007, p.1143-1148.</ref>

<ref name=echi2007>Takuya Echigo, Mitsuyoshi Kimata, and Teruyuki Maruoka (2007): "Crystal-chemical and carbon-isotopic characteristics of karpatite (C<sub>24</sub>H<sub>12</sub>) from the Picacho Peak Area, San Benito County, California: Evidences for the hydrothermal formation". ''American Mineralogist'', volume 92, issues 8-9, pages 1262–1269. Note: the name should be spelled "carpathite". {{doi|10.2138/am.2007.2509}}</ref>

</references>

{{Commons category|Evenkite|position=left}}

Category:Organic minerals
Category:Orthorhombic minerals
Category:Minerals in space group 57
Category:Luminescent minerals
Category:Minerals described in 1953

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Adapted from the Wikipedia article [Evenkite](https://en.wikipedia.org/wiki/Evenkite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Evenkite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.