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Gurzhiite
A valid IMA mineral species
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About Gurzhiite
Formula:
Al(UO2)(SO4)2F · 10H2O
Colour:
Pale yellow (crystals) to lemon yellow (aggregates)
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
2.52
Crystal System:
Triclinic
Name:
Honors Russian mineralogist and crystallographer, Dr. Vladislav V. Gurzhiy (Владислав Васильевич Гуржий), due to his contributions to uranium mineralogy and crystallography.
A lower hydrate counterpart of strassmannite, being structurally different from it.
Crystal structure details:
* based on uranyl-sulfate chains, topologically resembling these in bobcookite or svornostite group;
* intra-chain Al-octahedra are: Al1(H2O)6 and Al2F2(H2O)4;
* a complex network of H-bonds.
Crystal structure details:
* based on uranyl-sulfate chains, topologically resembling these in bobcookite or svornostite group;
* intra-chain Al-octahedra are: Al1(H2O)6 and Al2F2(H2O)4;
* a complex network of H-bonds.
Unique Identifiers
Mindat ID:
55758
Long-form identifier:
mindat:1:1:55758:6
IMA Classification of Gurzhiite
Classification of Gurzhiite
7.EB.
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
E : Uranyl sulfates
B : With medium-sized cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
E : Uranyl sulfates
B : With medium-sized cations
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 |
|---|---|---|
| Grz | 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 Gurzhiite
Vitreous
Transparency:
Transparent
Colour:
Pale yellow (crystals) to lemon yellow (aggregates)
Streak:
White
Hardness:
2 on Mohs scale
Comment:
ca.
Tenacity:
Brittle
Cleavage:
Distinct/Good
on {001}
on {001}
Fracture:
Irregular/Uneven
Density:
2.52(3) g/cm3 (Measured) 2.605 g/cm3 (Calculated)
Optical Data of Gurzhiite
Type:
Biaxial (-)
RI values:
nα = 1.528(3) nβ = 1.538(2) nγ = 1.544(3)
2V:
Measured: 80° (10), Calculated: 75.1°
Max. Birefringence:
δ = 0.016
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:
None to Very Low
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.
Chemistry of Gurzhiite
Mindat Formula:
Al(UO2)(SO4)2F · 10H2O
Element Weights:
Crystallography of Gurzhiite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 7.193(2) Å, b = 11.760(2) Å, c = 11.792(2) Å
α = 67.20(3)°, β = 107.76(3)°, γ = 89.99(3)°
α = 67.20(3)°, β = 107.76(3)°, γ = 89.99(3)°
Ratio:
a:b:c = 0.612 : 1 : 1.003
Unit Cell V:
867.72 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 10.24 Å | (100) |
| 6.76 Å | (10) |
| 5.40 Å | (14) |
| 5.11 Å | (54) |
| 3.618 Å | (8) |
| 3.405 Å | (11) |
| 3.348 Å | (7) |
| 3.065 Å | (11) |
Type Occurrence of Gurzhiite
General Appearance of Type Material:
Fine-grained aggregates, comprising bladed crystals up to 0.1 mm across, forming veinlets up to 50 cm long, in cracks of a brecciated rock.
Place of Conservation of Type Material:
Collections of the Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18–2, Moscow 119071, Russia, registration number 5756/1.
Geological Setting of Type Material:
Uranium deposit.
Associated Minerals at Type Locality:
Synonyms of Gurzhiite
Other Language Names for Gurzhiite
Related Minerals - Strunz-mindat Grouping
| 7.EB. | Bobcookite | NaAl(UO2)2(SO4)4 · 18H2O |
| 7.EB. | Zincorietveldite | Zn(UO2)(SO4)2(H2O)5 |
| 7.EB. | Chenowethite | Mg(H2O)6[(UO2)2(SO4)2(OH)2] · 5H2O |
| 7.EB.I | Shinarumpite | [Co(H2O)6][(UO2)(SO4)2(H2O)] · 4H2O |
| 7.EB. | Alwilkinsite-(Y) | Y(UO2)3(SO4)2O(OH)3(H2O)7 · 7H2O |
| 7.EB.05 | Johannite | Cu(UO2)2(SO4)2(OH)2 · 8H2O |
| 7.EB.05 | Meitnerite | (NH4)(UO2)(SO4)(OH) · 2H2O |
| 7.EB.10 | Rietveldite | Fe(UO2)(SO4)2(H2O)5 |
| 7.EB.10 | Deliensite | Fe[(UO2)2(SO4)2(OH)2](H2O)7 |
| 7.EB.15 | Strassmannite | Al(UO2)(SO4)2F · 16H2O |
| 7.EB.15 | Leydetite | Fe(UO2)(SO4)2 · 11H2O |
| 7.EB.15 | Magnesioleydetite | Mg(UO2)(SO4)2 · 11H2O |
| 7.EB.20 | Greenlizardite | (NH4)Na(UO2)2(SO4)2(OH)2 · 4H2O |
| 7.EB.25 | Markcooperite | Pb2(UO2)(TeO6) |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 34.5829% | 8,645,725 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 0.0000% | 0 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Fluorescence of Gurzhiite
Bright yellow-green (both SWUV and LWUV).
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 Gurzhiite
mindat.org URL:
https://www.mindat.org/min-55758.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Gurzhiite
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 65. European Journal of Mineralogy, 34 (1) 143-148 doi:10.5194/ejm-34-143-2022
Kasatkin, Anatoly V., Plášil, Jakub, Chukanov, Nikita V., Škoda, Radek, Nestola, Fabrizio, Agakhanov, Atali A., Belakovskiy, Dmitry I. (2022) Gurzhiite, Al(UO2)(SO4)2F⋅10H2O, a new uranyl sulfate mineral with a chain structure from the Bykogorskoe deposit, Northern Caucasus, Russia. Mineralogical Magazine, 86 (3) 412-421 doi:10.1180/mgm.2022.34
Localities for Gurzhiite
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) | |
| Miyawaki et al. (2022) +1 other reference |
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Mine no. 2, Byk Mountain, Predgorny District, Stavropol Krai, Russia