Wulffite
A valid IMA mineral species
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About Wulffite
Georgiy V. Wulff
Formula:
K3NaCu4O2(SO4)4
Colour:
Dark green with bluish hue or deep emerald-green.
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
3.23
Crystal System:
Orthorhombic
Name:
Named in honor of the Russian crystallographer Georgiy Viktorovich Wulff (22 June 1863, Nizhyn (Russian Empire, nowadays Ukraine) – 25 December 1925, Moscow), who suggested the model of X-ray interference in crystals (1913).
Related to parawulffite in terms of both chemistry and structure. One of 4 K-Na-Cu sulfate minerals beside euchlorine, parawulffite, and piypite.
Structure details: (1) the heteropolyhedral quasi-framework of Cu–O–S, along [010], and NaO6 octahedra chains ; (2) Cu–O–S chains comprise Cu-centered square pyramids ([4+1] coordination of Cu) and sulfate tetrahedra; (3) different ratios of alkali cations and their arrangement in cavities of the quasi-framework when compared to parawulffite; (4) different configuration of Cu–O–S chains than that in parawulffite.
Structure details: (1) the heteropolyhedral quasi-framework of Cu–O–S, along [010], and NaO6 octahedra chains ; (2) Cu–O–S chains comprise Cu-centered square pyramids ([4+1] coordination of Cu) and sulfate tetrahedra; (3) different ratios of alkali cations and their arrangement in cavities of the quasi-framework when compared to parawulffite; (4) different configuration of Cu–O–S chains than that in parawulffite.
Unique Identifiers
Mindat ID:
43897
Long-form identifier:
mindat:1:1:43897:1
Similar Names
| Wolfeite | A valid IMA mineral species - grandfathered | Fe22+(PO4)(OH) |
| Wulfenite | A valid IMA mineral species - grandfathered | Pb(MoO4) |
| Wülfingite | A valid IMA mineral species | Zn(OH)2 |
IMA Classification of Wulffite
Classification of Wulffite
7.BC.60
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
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 |
|---|---|---|
| Wlf | 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 Wulffite
Vitreous
Transparency:
Transparent
Colour:
Dark green with bluish hue or deep emerald-green.
Streak:
Light green
Hardness:
2½ on Mohs scale
Cleavage:
Perfect
2 perfect cleavages || elongation; additional one, coplanar to (010)
2 perfect cleavages || elongation; additional one, coplanar to (010)
Fracture:
Step-Like
Density:
3.23(2) g/cm3 (Measured) 3.19 g/cm3 (Calculated)
Optical Data of Wulffite
Type:
Biaxial (+)
RI values:
nα = 1.582(3) nβ = 1.610(3) nγ = 1.715(3)
2V:
Calculated: 58°
Max. Birefringence:
δ = 0.133
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:
High (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 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.
Pleochroism:
Strong
Comments:
emerald-green (Z), medium-saturation green (Y), Z > Y
Chemistry of Wulffite
Mindat Formula:
K3NaCu4O2(SO4)4
Element Weights:
Common Impurities:
Rb,Cs
Crystallography of Wulffite
Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Cell Parameters:
a = 14.2810(6) Å, b = 4.9478(2) Å, c = 24.113(1) Å
Ratio:
a:b:c = 2.886 : 1 : 4.873
Unit Cell V:
1703.79 ų
Z:
4
Morphology:
coarse prismatic crystals up to 1.2 × 2 mm, in clusters and crusts; [010] elongation
Comment:
Space group is Pn21a
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.27 Å | (100) |
| 7.16 Å | (22) |
| 3.125 Å | (16) |
| 2.882 Å | (16) |
| 2.780 Å | (33) |
| 2.725 Å | (14) |
| 2.472 Å | (20) |
| 2.366 Å | (13) |
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 45a : [Sulfates, arsenates, selenates, antimonates] |
Type Occurrence of Wulffite
General Appearance of Type Material:
prisms
Place of Conservation of Type Material:
Type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 4385/1
Geological Setting of Type Material:
incrustations on (1) basaltic scoria, (2) tenorite or (3) aphthitalite
Associated Minerals at Type Locality:
Synonyms of Wulffite
Other Language Names for Wulffite
Common Associates
Associations Based on Photo Data:
| 1 photo of Wulffite associated with Kozyrevskite | Cu4O(AsO4)2 |
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.30 | Fedotovite | K2Cu3(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 | 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) | 14.4680% | 4,485 | 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:
[cm-1]: ~1223, 1198, 1153s, 1118s (asymmetric stretching of sulfate), 1026s, 989s (symmetric stretching of sulfate), 671, 645sh, 635, 612 (bending of sulfate), 535sh, 511 (lattice modes: stretching of shorter bonds in Cu-centered polyhedra and
Notes:
slowly dissolves in RT water
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 Wulffite
mindat.org URL:
https://www.mindat.org/min-43897.html
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References for Wulffite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) New minerals and nomenclature modifications approved in 2013. CNMNC Newsletter No.17. Mineralogical Magazine, 77 (7) 2997-3005 doi:10.1180/minmag.2013.077.7.09
Pekov, I. V., Zubkova, N. V., Yapaskurt, V. O., Belakovskiy, D. I., Chukanov, N. V., Lykova, I. S., Savelyev, D. P., Sidorov, E. G., Pushcharovsky, D. Y. (2014) Wulffite, K3NaCu4O2(SO4)4, and parawulffite, K5Na3Cu8O4(SO4)8, two new minerals from fumarole sublimates of the Tolbachik Volcano, Kamchatka, Russia. The Canadian Mineralogist, 52 (4) 699-716 doi:10.3749/canmin.1400018
Localities for Wulffite
Showing 2 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) | |
| Williams et al. (2013) +4 other references |
| Zelenski et al. (2020) |
Quick NavTopAbout WulffiteUnique IdentifiersSimilar NamesIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
Arsenatnaya fumarole, Second scoria cone, Northern Breakthrough, Great Fissure eruption, Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia