Fedotovite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Fedotovite
Sergei A. Fedotov
Formula:
K2Cu3(SO4)3O
Colour:
Emerald green to grass green
Lustre:
Vitreous, Silky
Hardness:
2½
Specific Gravity:
3.205
Crystal System:
Monoclinic
Name:
Named in honor of Sergei Aleksandrovich Fedotov (Сергей Александрович Федотов) (19 March 1931, Leningra, USSR – 20 August 2019), volcanologist and seismologist, Director of the Institute of Volcanology, Petropavlovsk-Kamchatkskii, Russia.
Unique Identifiers
Mindat ID:
1469
Long-form identifier:
mindat:1:1:1469:0
Similar Names
| Fedorovite | A variety of Aegirine | NaFe3+Si2O6 |
IMA Classification of Fedotovite
Approved
IMA Formula:
K2Cu2+3O(S6+O4)3
Approval year:
1986
First published:
1988
Classification of Fedotovite
7.BC.30
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
B : Sulfates (selenates, etc.) with additional anions, without H2O
C : With medium-sized and large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
B : Sulfates (selenates, etc.) with additional anions, without H2O
C : With medium-sized and large cations
30.3.4.1
30 : ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN
3 : (AB)5(XO4)3Zq
30 : ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN
3 : (AB)5(XO4)3Zq
25.2.14
25 : Sulphates
2 : Sulphates of Cu and Ag
25 : Sulphates
2 : Sulphates of Cu and Ag
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 |
|---|---|---|
| Fdt | 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 Fedotovite
Vitreous, Silky
Transparency:
Transparent
Colour:
Emerald green to grass green
Streak:
Pale grass green
Hardness:
2½ on Mohs scale
Cleavage:
Perfect
on {100}
on {100}
Density:
3.205(3) g/cm3 (Measured) 3.09 g/cm3 (Calculated)
Optical Data of Fedotovite
Type:
Biaxial (+)
RI values:
nα = 1.577 nβ = 1.594 nγ = 1.633
2V:
Measured: 68° , Calculated: 70°
Max. Birefringence:
δ = 0.056
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
Dispersion:
very weak
Optical Extinction:
Z = b; Y ∧ c ≃ 0°.
Pleochroism:
Visible
Comments:
X = greenish blue; Y = Z = yellow green.
Comments:
Absorption: Z > Y.
Chemistry of Fedotovite
Mindat Formula:
K2Cu3(SO4)3O
Element Weights:
Elements listed:
Crystallography of Fedotovite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Cell Parameters:
a = 19.037(6) Å, b = 9.479(2) Å, c = 14.231(5) Å
β = 111.04°
β = 111.04°
Ratio:
a:b:c = 2.008 : 1 : 1.501
Unit Cell V:
2,396.80 ų (Calculated from Unit Cell)
Z:
8
Morphology:
Crusts of pseudohexagonal flakes.
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) |
|---|---|---|---|---|---|---|---|
| 0014494 | Fedotovite | Starova G L, Filatov S K, Fundamensky V S, Vergasova L P (1991) The crystal structure of fedotovite, K2Cu3O(SO4)3 Mineralogical Magazine 55 613-616 |  | 1991 | Tolbachik fissure eruption, Kamchatka Peninsula, Russia | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.83 Å | (100) |
| 6.59 Å | (4) |
| 6.54 Å | (4) |
| 4.405 Å | (3) |
| 4.207 Å | (3) |
| 2.943 Å | (12) |
| 2.844 Å | (5) |
Comments:
Tolbachik volcano, Russia. Data from the type description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 45a : [Sulfates, arsenates, selenates, antimonates] | |
| 45b : [Other oxidized fumarolic minerals] |
Geological Setting:
Sublimates around fumaroles.
Type Occurrence of Fedotovite
General Appearance of Type Material:
Aggregates of poorly developed platy to micaceous crystals and fine-grained crusts 1 to 2 mm thick. Crystals are up to 5 mm long x 0.1-1 mm thick, flattened on {100} and irregular in outline. Rarely rectangular or pseudohexagonal.
Place of Conservation of Type Material:
Mining Museum, St. Petersburg, Russia, number 1890/1 (type).
Geological Setting of Type Material:
Fumarole.
Associated Minerals at Type Locality:
Synonyms of Fedotovite
Other Language Names for Fedotovite
Common Associates
Associations Based on Photo Data:
| 3 photos of Fedotovite associated with Chalcocyanite | CuSO4 |
| 3 photos of Fedotovite associated with Chalcanthite | CuSO4 · 5H2O |
| 2 photos of Fedotovite associated with Euchlorine | KNaCu3(SO4)3O |
| 1 photo of Fedotovite associated with Kamchatkite | KCu3(SO4)2OCl |
| 1 photo of Fedotovite associated with Dolerophanite | Cu2(SO4)O |
Related Minerals - Strunz-mindat Grouping
| 7.BC. | Viskontite | Pb5Cu2(SO4)3(SeO3)(OH)6 |
| 7.BC. | Zincochenite | Pb4Zn(OH)6(SO4)2 |
| 7.BC. | D'Ansite-(Mn) | Na21Mn2+(SO4)10Cl3 |
| 7.BC. | D'Ansite-(Fe) | Na21Fe2+(SO4)10Cl3 |
| 7.BC. | Acmonidesite | (NH4,K,Pb)8NaFe2+4(SO4)5Cl8 |
| 7.BC. | Adranosite | (NH4)4NaAl2(SO4)4Cl(OH)2 |
| 7.BC. | Chromviskontite | Pb5Cu2(CrO4)3(SeO3)(OH)6 |
| 7.BC. | Backite | Pb2AlTeO6Cl |
| 7.BC. | Adranosite-(Fe) | (NH4)4NaFe3+2(SO4)4Cl(OH)2 |
| 7.BC. | Agaite | Pb3CuTeO5(OH)2(CO3) |
| 7.BC. | Wildcatite | CaFe3+Te6+O5(OH) |
| 7.BC. | Hagstromite | Pb8Cu2+(Te6+O6)2(CO3)Cl4 |
| 7.BC.05 | D'Ansite | Na21Mg(SO4)10Cl3 |
| 7.BC.07 | 'Apatelite' | Fe3(SO4)2(OH)5 · 0.5H2O |
| 7.BC.07 | 'Unnamed (Ba-Fe Vanadate)' | Ba, Fe, V, O, H |
| 7.BC.10 | Jarosite | KFe3+3(SO4)2(OH)6 |
| 7.BC.10 | Dorallcharite | TlFe3+3(SO4)2(OH)6 |
| 7.BC.10 | Argentojarosite | AgFe3+3(SO4)2(OH)6 |
| 7.BC.10 | Natroalunite | NaAl3(SO4)2(OH)6 |
| 7.BC.10 | Natrojarosite | NaFe3(SO4)2(OH)6 |
| 7.BC.10 | Beaverite-(Cu) | Pb(Fe3+2Cu)(SO4)2(OH)6 |
| 7.BC.10 | Beaverite-(Zn) | Pb(Fe3+2Zn)(SO4)2(OH)6 |
| 7.BC.10 | Walthierite | Ba0.5Al3(SO4)2(OH)6 |
| 7.BC.10 | Huangite | Ca0.5Al3(SO4)2(OH)6 |
| 7.BC.10 | 'Natroalunite-2c' | (Na,Ca0.5,K)Al3(SO4)2(OH)6 |
| 7.BC.10 | Alunite | KAl3(SO4)2(OH)6 |
| 7.BC.10 | Plumbojarosite | Pb0.5Fe3+3(SO4)2(OH)6 |
| 7.BC.10 | Karlseifertite | Pb(Ga2Ge)(AsO4)2(OH)6 |
| 7.BC.10 | Hydroniumjarosite | (H3O)Fe3+3(SO4)2(OH)6 |
| 7.BC.10 | Ammonioalunite | (NH4)Al3(SO4)2(OH)6 |
| 7.BC.10 | Ammoniojarosite | (NH4)Fe3+3(SO4)2(OH)6 |
| 7.BC.10 | Osarizawaite | Pb(Al2Cu2+)(SO4)2(OH)6 |
| 7.BC.10 | Schlossmacherite | (H3O)Al3(SO4)2(OH)6 |
| 7.BC.15 | Ye'elimite | Ca4Al6(SO4)O12 |
| 7.BC.20 | Nabokoite | KCu7(SO4)5(Te4+O3)OCl |
| 7.BC.20 | Puninite | Na2Cu3O(SO4)3 |
| 7.BC.20 | Atlasovite | K(BiO)Cu6Fe3+(SO4)5O3Cl |
| 7.BC.25 | Chlorothionite | K2Cu(SO4)Cl2 |
| 7.BC.30 | Euchlorine | KNaCu3(SO4)3O |
| 7.BC.35 | Kamchatkite | KCu3(SO4)2OCl |
| 7.BC.40 | Piypite | K4Cu4O2(SO4)4 · (Na,Cu)Cl |
| 7.BC.45 | Alumoklyuchevskite | K3Cu3(Al,Fe3+)(SO4)4O2 |
| 7.BC.45 | Belousovite | KZn(SO4)Cl |
| 7.BC.45 | Klyuchevskite | K3Cu3(Fe3+,Al)(SO4)4O2 |
| 7.BC.47 | Müllerite | Pb2Fe3+(Te6+O6)Cl |
| 7.BC.50 | Caledonite | Pb5Cu2(SO4)3(CO3)(OH)6 |
| 7.BC.50 | Elasmochloite | Na3Cu6BiO4(SO4)5 |
| 7.BC.52 | Eleomelanite | (K2Pb)Cu4O2(SO4)4 |
| 7.BC.55 | Falgarite | K4(VO)3(SO4)5 |
| 7.BC.55 | Wherryite | Pb7Cu2(SO4)4(SiO4)2(OH)2 |
| 7.BC.57 | Krasheninnikovite | KNa2CaMg(SO4)3F |
| 7.BC.60 | Wulffite | K3NaCu4O2(SO4)4 |
| 7.BC.60 | Parawulffite | K5Na3Cu8O4(SO4)8 |
| 7.BC.60 | Mammothite | Pb6Cu4AlSb5+O2(OH)16Cl4(SO4)2 |
| 7.BC.62 | Shuvalovite | K2(Ca2Na)(SO4)3F |
| 7.BC.65 | Saccoite | Ca2Mn3+2F(OH)8 · 0.5(SO4) |
| 7.BC.65 | Linarite | PbCu(SO4)(OH)2 |
| 7.BC.65 | Therasiaite | (NH4)3KNa2Fe2+Fe3+(SO4)3Cl5 |
| 7.BC.65 | Franksousaite | PbCu(Se6+O4)(OH)2 |
| 7.BC.65 | Munakataite | Pb2Cu2(Se4+O3)(SO4)(OH)4 |
| 7.BC.65 | Schmiederite | Pb2Cu2(Se6+O4)(Se4+O3)(OH)4 |
| 7.BC.70 | Chenite | Pb4Cu(SO4)2(OH)6 |
| 7.BC.75 | Krivovichevite | Pb3Al(OH)6(SO4)(OH) |
| 7.BC.80 | Anhydrokainite | KMg(SO4)Cl |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 13.6464% | 4,230 | 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
Other Information
IR Spectrum:
IR spectrum shows features at 600 cm-1 and 1100 cm-1 due to (SO4)2- groups. An absence of features at 1600 and 3400-3600 cm-1 indicates that no water or hydroxyl is present.
Thermal Behaviour:
DTA curve shows two endothermic effects: one at 692°C with no weight loss (breakdown with formation of tenorite), and another at 715°C with a 20 wt% loss (desulfatization).
Special Storage/
Display Requirements:
Display Requirements:
Unstable in air.
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 Fedotovite
mindat.org URL:
https://www.mindat.org/min-1469.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 Fedotovite
Reference List:
Siidra, Oleg I., Nazarchuk, Evgenii V., Zaitsev, Anatoly N., Lukina, Evgeniya A., Avdontseva, Evgeniya Y., Vergasova, Lidiya P, Vlasenko, Natalia S., Filatov, Stanislav K., Turner, Rick, Karpov, Gennady A. (2017) Copper oxosulphates from fumaroles of Tolbachik volcano: puninite, Na2Cu3O(SO4)3 – a new mineral species and structure refinements of kamchatkite and alumoklyuchevskite. European Journal of Mineralogy, 29 (3) 499-510 doi:10.1127/ejm/2017/0029-2619
Localities for Fedotovite
Showing 8 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.
Italy | |
| Pellino et al. (2025) |
Russia (TL) | |
| Vergasova et al. (1988) +1 other reference |
| Pekov et al. (2013) |
| Pekov et al. (2018) +1 other reference | |
| Bykova et al. (1998) | |
| Zelenski et al. (2012) +1 other reference | |
| Sharygin et al. (2018) |
USA | |
| Castor et al. (2004) |
Quick NavTopAbout FedotoviteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
Yadovitaya fumarole, Second scoria cone, Northern Breakthrough, Great Fissure eruption, Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia