Evenkite
A valid IMA mineral species - grandfathered
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About Evenkite
Formula:
C23H50
although the formula was formerly given as C24H50 (tetracosane), the situation is much more complex; the above formula corresponds to the prevailing (20%) homologue (tricosane), thus actually does not represent the complex composition; a more general formula is CnH2n+2 that represents the paraffin series; see details below
Hardness:
1
Crystal System:
Orthorhombic
Name:
Named for the Evenkia district, Russia, that includes the type locality.
A paraffin wax that is a homogenous crystalline solid solution (Platonova & Kotel'nikova, 2007), with n-tricosane being dominant.
Apparently identical to hatchettite (Spangenberg & Meisser, 2000).
A ten-component (homologues) mixture mainly (98%) comprises normal (chain) paraffins, with the remainder being iso- and cycloparaffins. Half of the major homologues are even, and the other half - odd. The C atom count is in the 19-28 (n) range. Distribution, based on n, is nearly symmetrical.
To make the situation even more complex, in the 26-30 oC range, evenkite's crystalline state passes to low-temperature rotary-crystalline state. In the latter state, the particular molecules have fixed structural positions, but may rotate.
Apparently identical to hatchettite (Spangenberg & Meisser, 2000).
A ten-component (homologues) mixture mainly (98%) comprises normal (chain) paraffins, with the remainder being iso- and cycloparaffins. Half of the major homologues are even, and the other half - odd. The C atom count is in the 19-28 (n) range. Distribution, based on n, is nearly symmetrical.
To make the situation even more complex, in the 26-30 oC range, evenkite's crystalline state passes to low-temperature rotary-crystalline state. In the latter state, the particular molecules have fixed structural positions, but may rotate.
Unique Identifiers
Mindat ID:
1428
Long-form identifier:
mindat:1:1:1428:7
IMA Classification of Evenkite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
C23H48
Classification of Evenkite
10.BA.50
10 : ORGANIC COMPOUNDS
B : Hydrocarbons
A : Hydrocarbons
10 : ORGANIC COMPOUNDS
B : Hydrocarbons
A : Hydrocarbons
50.3.6.1
50 : ORGANIC COMPOUNDS
3 : Hydrocarbons
50 : ORGANIC COMPOUNDS
3 : Hydrocarbons
32.1
32 : Hydrocarbons, Resins and other Organic Compounds
32 : Hydrocarbons, Resins and other Organic Compounds
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Evk | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Evenkite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Evenkite
Hardness:
1 on Mohs scale
Optical Data of Evenkite
Type:
Biaxial (+)
RI values:
nα = 1.504 nβ = 1.504 nγ = 1.553
Max. Birefringence:
δ = 0.049
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Low (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
No measured or calculated 2V is on file for this mineral, so the value used here (0°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
No measured or calculated 2V is on file for this mineral, so the value used here (0°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
none
Chemistry of Evenkite
Mindat Formula:
C23H50
although the formula was formerly given as C24H50 (tetracosane), the situation is much more complex; the above formula corresponds to the prevailing (20%) homologue (tricosane), thus actually does not represent the complex composition; a more general formula is CnH2n+2 that represents the paraffin series; see details below
although the formula was formerly given as C24H50 (tetracosane), the situation is much more complex; the above formula corresponds to the prevailing (20%) homologue (tricosane), thus actually does not represent the complex composition; a more general formula is CnH2n+2 that represents the paraffin series; see details below
Elements listed:
Crystallography of Evenkite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pbcm
Cell Parameters:
a = 7.47 Å, b = 4.98 Å, c = 65.85 Å
Ratio:
a:b:c = 1.5 : 1 : 13.223
Unit Cell V:
2450 ų
Z:
4
Comment:
homogenous crystalline solid solution, with (00l), (200) and (hkl) reflections representing the two-layer cell typical of paraffins; cell parameters for the synthetic counterpart are: a=7.474(1), b=4.980(1), c=65.85(3); the 00l reflections' positions corresponds to the 24-carbon (n-tetracosane) homologue; the rule of polarity of compositional/chemical deformations explains small shifts the n (carbon atom count), leading to variations in the c parameters' values (Platonova & Kotel'nikova, 2007)
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.18 Å | (100) |
| 3.74 Å | (90) |
| 2.25 Å | (80) |
| 2.52 Å | (70) |
| 2.12 Å | (60) |
| 1.751 Å | (60) |
| 3.02 Å | (50) |
Comments:
Evenkia district, Russia. ICDD 28-2004.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3a: Earth’s earliest Hadean crust | >4.50 |
| 10 : Basalt-hosted zeolite minerals | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 50 : Coal and/or oil shale minerals | <0.36 |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) |
Type Occurrence of Evenkite
Other Language Names for Evenkite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 10.BA. | Freitalite | C14H10 |
| 10.BA.05 | Fichtelite | C19H34 |
| 10.BA.10 | Branchite | C20H34 |
| 10.BA.15 | Dinite | C20H36 |
| 10.BA.20 | Idrialite | C22H14 |
| 10.BA.25 | Kratochvílite | C13H10 |
| 10.BA.30 | Carpathite | C24H12 |
| 10.BA.35 | Phylloretine | C18H18 |
| 10.BA.40 | Ravatite | C14H10 |
| 10.BA.45 | Simonellite | C19H24 |
| 10.BA.55 | Wampenite | C18H16 |
| 10.BA.60 | 'Scharizerite' |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Evenkite
mindat.org URL:
https://www.mindat.org/min-1428.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Evenkite
Localities for Evenkite
Showing 10 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
France | |
| |
| Wolfgang E. Henkel collection |
| Lapis 34 (3) |
Greenland | |
| Petersen (2001) |
Hungary | |
| collector: János Nyúl |
Russia (TL) | |
| Pekov (1998) |
Slovakia | |
| Koděra et al. (1986) |
| Pauliš |
| Ďuďa |
Tunisia | |
| Somrani et al. (2025) |
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Slávik adit, Dubník, Červenica, Prešov District, Prešov Region, Slovakia