Julienite
A valid IMA mineral species - grandfathered
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About Julienite
Henri Julien
Formula:
Na2[Co(SCN)4] · 8H2O
Colour:
Blue
Lustre:
Sub-Vitreous, Greasy, Silky
Specific Gravity:
1.648
Crystal System:
Monoclinic
Name:
Named in 1928 by Alfred Schoep in honor of a recently deceased Sorbonne University (Paris) Ph. D. student, Henri Julien [c. 1887 Clermont-Ferrand, Auvergne, France - December 1, 1920, Kambove, Katanga, Belgian Congo], who was a member of a geological survey mission in the Congo when he succumbed to poor health at the young age of 33. Julien had wanted to follow in his father's career as a geologist.
Sodium tetrathiocyanatocobaltate(II) octahydrate - a complex salt. Compare natrosulfatourea (that, however, lacks cobalt).
A very rare lath-like blue mineral occurring as crusts permeating matrix.
According to the state of art, julienite is the single mineral species containing the thiocyanate anion. Compare 'kafehydrocyanite'.
A very rare lath-like blue mineral occurring as crusts permeating matrix.
According to the state of art, julienite is the single mineral species containing the thiocyanate anion. Compare 'kafehydrocyanite'.
Unique Identifiers
Mindat ID:
2121
Long-form identifier:
mindat:1:1:2121:6
Similar Names
| Jelinite | A variety of 'Amber' | C10H16O + (H2S) |
| Julianite | A synonym of Tennantite Subgroup |
IMA Classification of Julienite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Na2Co2+(S2-CN3-)4·8H2O
First published:
1928
Classification of Julienite
10.AD.05
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
D : Cyanates
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
D : Cyanates
50.2.3.1
50 : ORGANIC COMPOUNDS
2 : Mellitates, Citrates, Cyanates, Acetates and Formates
50 : ORGANIC COMPOUNDS
2 : Mellitates, Citrates, Cyanates, Acetates and Formates
30.1
30 : Thiocyanates
30 : Thiocyanates
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 |
|---|---|---|
| Jln | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Julienite
Sub-Vitreous, Greasy, Silky
Transparency:
Transparent, Translucent
Colour:
Blue
Streak:
Blue
Comment:
Hardness not determined.
Tenacity:
Brittle
Density:
1.648 g/cm3 (Measured) 1.61 g/cm3 (Calculated)
Optical Data of Julienite
Type:
Uniaxial (+)
RI values:
nω = 1.556 nε = 1.645
Max. Birefringence:
δ = 0.089
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:
Moderate (positive)
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 uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Optical Extinction:
Parallel.
Chemistry of Julienite
Mindat Formula:
Na2[Co(SCN)4] · 8H2O
Element Weights:
Crystallography of Julienite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 18.941 Å, b = 19.209 Å, c = 5.460 Å
β = 91.64°
β = 91.64°
Ratio:
a:b:c = 0.986 : 1 : 0.284
Unit Cell V:
1,985.74 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Crystals as minute needles, elongated [001], aggregated into crusts; acicular [001].
Twinning:
On {110} as the twin plane, or around [001].
Comment:
Pseudotetragonal. Space Group = P21/n, based on synthetic material.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0009760 | Julienite | Mereiter K, Preisinger A (1982) The structure of sodium tetraisothiocyanatocobaltate(II) octahydrate Na2[Co(NCS)4]*8H2O Acta Crystallographica B38 1084-1088 |  | 1982 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 0.935 Å | (100) |
| 0.903 Å | (100) |
| 3.55 Å | (85) |
| 3.23 Å | (85) |
| 1.375 Å | (85) |
| 1.220 Å | (85) |
| 6.50 Å | (58) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 50 : Coal and/or oil shale minerals | <0.36 |
Type Occurrence of Julienite
General Appearance of Type Material:
Blue incrustations.
Place of Conservation of Type Material:
Ecole Nationale Supérieure des Mines, Paris, France, number 5082.
Geological Setting of Type Material:
White talc schist.
Associated Minerals at Type Locality:
Other Language Names for Julienite
Related Minerals - Strunz-mindat Grouping
| 10.AD.10 | 'Kafehydrocyanite' | K4[Fe(CN)6] · H2O |
Other Information
Notes:
Readily soluble in water, soluble in alcohol, yielding a pink solution.
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 Julienite
mindat.org URL:
https://www.mindat.org/min-2121.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Julienite
Localities for Julienite
Showing 1 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.
DR Congo (TL) | |
| Schoep et al. (1935) +3 other references |
Quick NavTopAbout JulieniteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesStrunz-MindatOther InformationInternet Links References Localities Locality List
Shamitumba, Shinkolobwe, Kambove Territory, Haut-Katanga, DR Congo