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Yegorovite
A valid IMA mineral species
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About Yegorovite
Yuriy K. Yegorov-Tismenko
Formula:
Na4[Si4O8(OH)4] · 7H2O
Colour:
Colorless
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
1.90
Crystal System:
Monoclinic
Name:
Named in honor of Yuriy Klavdievich Yegorov-Tismenko (Юрий Клавдиевич Егоров-Тисменко) (26 May 1938 - 16 July 2007) crystal chemist, crystallographer, at the Moscow State University. He won the 2003 Lomonosov Prize for teaching.
The first natural sodium silicate with single zig-zag chains of Si tetrahedra.
Unique Identifiers
Mindat ID:
38851
Long-form identifier:
mindat:1:1:38851:5
IMA Classification of Yegorovite
Approved
IMA Formula:
Na4[Si4O8(OH)4]·7H2O
Approval year:
2008
First published:
2010
Type description reference:
Classification of Yegorovite
9.00.
9 : SILICATES (Germanates)
0 :
0 :
9 : SILICATES (Germanates)
0 :
0 :
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 |
|---|---|---|
| Yeg | 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 Yegorovite
Vitreous
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
2 on Mohs scale
Cleavage:
Perfect
(010) and (001)
(010) and (001)
Fracture:
Splintery
Density:
1.90(2) g/cm3 (Measured) 1.92 g/cm3 (Calculated)
Optical Data of Yegorovite
Type:
Biaxial (-)
RI values:
nα = 1.474(2) nβ = 1.479(2) nγ = 1.482(2)
2V:
Measured: >70° , Calculated: 75°
Max. Birefringence:
δ = 0.008
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 (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.
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.
Optical Extinction:
X ∧ a ~ 15°; Y = c; Z = b.
Chemistry of Yegorovite
Mindat Formula:
Na4[Si4O8(OH)4] · 7H2O
Element Weights:
Elements listed:
Crystallography of Yegorovite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 9.8744(4) Å, b = 12.398(5) Å, c = 14.8973(7) Å
β = 104.675(5)°
β = 104.675(5)°
Ratio:
a:b:c = 0.796 : 1 : 1.202
Unit Cell V:
1764.29 ų
Z:
4
Morphology:
Prismatic to flattened, lamellar crystals.
Twinning:
Polysynthetic twinning is typical.
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
Remove metal-metal sticks
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) |
|---|---|---|---|---|---|---|---|
| 0012513 | Yegorovite | Zubkova N V, Pekov I V, Pushcharovskii D Y, Kazantsev S S (2009) Crystal structure of yegorovite Na4[Si4O8(OH)4]*7H2O Doklady Earth Sciences 427 814-818 | 2009 | Lovozero alkaline complex, Kola Peninsula, Russia | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.21 Å | (70) |
| 6.21 Å | (72) |
| 4.696 Å | (44) |
| 4.003 Å | (49) |
| 3.734 Å | (46) |
| 3.116 Å | (100) |
| 2.463 Å | (38) |
Locality:
Reference:
Comments:
Palitra pegmatite, Karnasurt mine, Russia. The data are from the type description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Yegorovite
General Appearance of Type Material:
Tiny colorless to semi-transparent coarse prismatic to flattened, lamellar crystals up to 1mm long, often associated with minor revdite and megacyclite.
Place of Conservation of Type Material:
Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, Russia.
Geological Setting of Type Material:
Late hydrothermal, low-temperature paragenesis in a peralkaline pegmatite.
Associated Minerals at Type Locality:
Synonyms of Yegorovite
Other Language Names for Yegorovite
Dutch:Yegoroviet
German:Yegorovit
Related Minerals - Strunz-mindat Grouping
| 9.00. | Clino-ferri-holmquistite | ◻Li2(Mg3Fe3+2)(Si8O22)(OH)2 |
| 9.00. | Mendigite | Mn2Mn2MnCa(Si3O9)2 |
| 9.00. | Alflarsenite | NaCa2Be3Si4O13(OH) · 2H2O |
| 9.00. | Bridgmanite Subgroup | ABSiO3 |
| 9.00. | Ferroericssonite | BaFe2+2 Fe3+(Si2O7)O(OH) |
| 9.00. | Zvyaginite | NaZnNb2Ti[Si2O7]2(OH,F)3(H2O)4+x (x < 1) |
| 9.00. | Burnettite | CaVAlSiO6 |
| 9.00. | Ferrisepiolite | (Fe3+,Fe2+,Mg)4((Si,Fe3+)6O15)(O,OH)2 · 6H2O |
| 9.00. | Chrysotile | Mg3(Si2O5)(OH)4 |
| 9.00. | 'Shkatulkalita' | |
| 9.00.15 va | 'Chromoamesite' | Mg2(Al,Cr)(AlSiO5)(OH)4 |
| 9.00.50 | Thornasite | Na12Th4+3(Si8O19)4 · 18H2O |
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 Yegorovite
mindat.org URL:
https://www.mindat.org/min-38851.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Yegorovite
Reference List:
Zubkova, N. V., Pekov, I. V., Pushcharovskii, D. Yu., Kazantsev, S. S. (2009) Crystal structure of yegorovite Na4[Si4O8(OH)4] · 7H2O. Doklady Earth Sciences, 427 (1) 814-818 doi:10.1134/s1028334x09050237
Pekov, I. V., Zubkova, N. V., Chukanov, N. V., Zadov, A. E., Grishin, V. G., Pushcharovsky, D. Yu. (2010) Yegorovite, Na4[Si4O8(OH)4]·7H2O, a new mineral from the Lovozero alkaline pluton, Kola Peninsula. Geology of Ore Deposits, 52 (7) 584-590 doi:10.1134/s107570151007007x
Localities for Yegorovite
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.
Russia (TL) | |
| Zubkova et al. (2009) +1 other reference |
Quick NavTopAbout YegoroviteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesStrunz-MindatOther InformationInternet Links References Localities Locality List
Palitra pegmatite, Karnasurt mine, Karnasurt Mountain, Lovozersky District, Murmansk Oblast, Russia