Evenkite

Hydrocarbon mineral


title: "Evenkite" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["organic-minerals", "orthorhombic-minerals", "minerals-in-space-group-57", "luminescent-minerals", "minerals-described-in-1953"] description: "Hydrocarbon mineral" topic_path: "general/organic-minerals" source: "https://en.wikipedia.org/wiki/Evenkite" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Hydrocarbon mineral ::

::data[format=table title="infobox mineral"]

FieldValue
nameEvenkite
imageEvenkite-444375.jpg
captionEvenkite from Dubnik, Slovakia
categoryOrganic mineral
formulaC24H50
IMAsymbolEvk
strunz10.BA.50
systemOrthorhombic
classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
symmetryPbcm
unit cella = 7.47, b = 4.98, c = 65.85 [Å]; Z = 4
colorColorless or pale yellow
habitTabular pseudohexagonal crystals, granular, disseminated
twinningPolysynthetic
cleavage{001} Perfect
mohs1
lusterWaxy
diaphaneityTransparent
gravity0.87
opticalpropBiaxial (+)
refractivenα = 1.504 nβ = 1.504 nγ = 1.553
birefringenceδ = 0.049
references
::

| name = Evenkite | boxwidth = | boxbgcolor = | image = Evenkite-444375.jpg | alt = | caption = Evenkite from Dubnik, Slovakia | category = Organic mineral | formula = C24H50 | IMAsymbol = Evk | molweight = | strunz = 10.BA.50 | dana = | system = Orthorhombic | class = Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) | symmetry = Pbcm | unit cell = a = 7.47, b = 4.98, c = 65.85 [Å]; Z = 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 = nα = 1.504 nβ = 1.504 nγ = 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 = Evenkite is a rare hydrocarbon mineral with formula C24H50; specifically, H3C–(CH2)22–CH3, the alkane n-tetracosane. It occurs as very soft (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.

Evenkite one of very few minerals that consist of crystalline hydrocarbons, which include carpathite (pure crystalline coronene, a polyaromatic hydrocarbon). It is also one of the few non-porous minerals that floats on water. It has been claimed to be the same as hatchettite.

History and geologic occurrence

Evenkite was first described in 1953 by A. V. Shropyshev, as found in the Khavokiperskiye deposit, Lower Tunguska River, Evenkiysky District, Siberia, Russia, where it occurs inside geodes and vugs in a quartz vein in welded tuff. It was named after the district. It has also been reported from the Hautes-Alpes region in France and the Slanské and Vihorlat mountains of Slovakia.

Evenkite appears as flaky wax partials on top of the quartz crystals. Associated minerals include quartz, chalcedony, pyrite, pyrrhotite, sphalerite, galena, chalcopyrite and calcite.

Evenkite was the last part of the geode to form. It is believed to have resulted from thermal cracking of the organic matter (mainly marine plants) that where trapped in the septarian concretions during the Jurassic burial, as the buried sediments were subjected to high pressure and temperatures. The French Alps region received a lot of geological uplift after the Jurassic burial.

References

References

  1. Warr, L.N.. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine.
  2. [http://www.mindat.org/min-1428.html Mindat.org]
  3. [http://webmineral.com/data/Evenkite.shtml Webmineral data]
  4. [http://rruff.geo.arizona.edu/doclib/hom/evenkite.pdf Handbook of Mineralogy]
  5. Skropyshev, A.V. "On Paraffin from a Base Metal Vein". Doklady Acad, 1953, P.717-719.
  6. 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.
  7. 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
  8. Pilonen, P.C. and Ercit, T.S. "New Mineral Names". American Mineralogist, 2005, p.1466-1469.
  9. Platonova, N.V. and Kotel'nikova, E.N. "Synthesis of Organic Mineral Evenkite". Geology of Ore Deposits, 2006, p.87-91.
  10. 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.
  11. 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.
  12. Takuya Echigo, Mitsuyoshi Kimata, and Teruyuki Maruoka (2007): "Crystal-chemical and carbon-isotopic characteristics of karpatite (C24H12) 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

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