Shinkolobweite
A valid IMA mineral species
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About Shinkolobweite
Formula:
Pb1.333[U5+O(OH)(UO2)5O4.67(OH)5.33](H2O)5
Colour:
dark reddish brown
Lustre:
Sub-Adamantine
Hardness:
2
Specific Gravity:
5.874 (Calculated)
Crystal System:
Orthorhombic
Name:
For the type locality
New structure type. Another mineral with confirmed U5+ after richetite, wyartite, and nollmotzite.
Crystal structure details:
* uranyl oxide-hydroxide sheets with β-U3O8 topology;
* they are commensurately modulated with (3 + 1) ordering due tolong-range ordering of U5+ and U6+ position and occupancy of the interlayer Pb atoms.
Crystal structure details:
* uranyl oxide-hydroxide sheets with β-U3O8 topology;
* they are commensurately modulated with (3 + 1) ordering due tolong-range ordering of U5+ and U6+ position and occupancy of the interlayer Pb atoms.
Unique Identifiers
Mindat ID:
51555
Long-form identifier:
mindat:1:1:51555:3
Similar Names
| Chinkolobwite | A synonym of Sklodowskite |
IMA Classification of Shinkolobweite
Classification of Shinkolobweite
4.GB.95
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
G : Uranyl Hydroxides
B : With additional cations (K, Ca, Ba, Pb, etc.); with mainly UO2(O,OH)5 pentagonal polyhedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
G : Uranyl Hydroxides
B : With additional cations (K, Ca, Ba, Pb, etc.); with mainly UO2(O,OH)5 pentagonal polyhedra
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 |
|---|---|---|
| Skw | 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 Shinkolobweite
Sub-Adamantine
Transparency:
Transparent
Colour:
Dark reddish brown
Streak:
Light bronze-yellow
Hardness:
2 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
perfect cleavage on {010}, imperfect cleavage on {100}
perfect cleavage on {010}, imperfect cleavage on {100}
Parting:
None
Fracture:
Irregular/Uneven
Comment:
even fracture
Density:
5.874 g/cm3 (Calculated)
Optical Data of Shinkolobweite
Type:
Biaxial (+)
RI values:
nα = 1.865(5) nβ = 1.875(5) nγ = 1.890(5)
2V:
Measured: 77° (1), Calculated: 79°
Max. Birefringence:
δ = 0.025
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:
Very 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.
Dispersion:
r>>v extreme
Pleochroism:
Visible
Comments:
X=orange-yellow, Y=yellow brown, Z= dark olive brown
Chemistry of Shinkolobweite
Mindat Formula:
Pb1.333[U5+O(OH)(UO2)5O4.67(OH)5.33](H2O)5
Element Weights:
Elements listed:
Chemical Analysis
Empirical formulas:
| Sample ID | Empirical Formula |
|---|---|
| 1 | Pb1.29U6+4.88U5+1.17O27H16.63 |
Sample references:
Crystallography of Shinkolobweite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pnnm
Setting:
Pnnm
Cell Parameters:
a = 14.4808(4) Å, b = 7.0681(8) Å, c = 11.9423(3) Å
Ratio:
a:b:c = 2.049 : 1 : 1.69
Unit Cell V:
1222.32 ų
Z:
2
Morphology:
Prisms flattened on {010}, are elongated on [001], and exhibit the forms {100}, {010}, {101}, and {10-1}.
Twinning:
None
Comment:
superspace group Pnnm(0b0)000; modulation wave vector [0 1/3 0]
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.27 Å | (27) |
| 3.614 Å | (15) |
| 3.486 Å | (49) |
| 3.149 Å | (100) |
| 2.519 Å | (15) |
| 2.031 Å | (15) |
| 1.993 Å | (23) |
| 1.771 Å | (16) |
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Type Occurrence of Shinkolobweite
General Appearance of Type Material:
Individual prismatic crystals measure up to 0.5 mm and are elongated on [001] and flattened on {010}
Place of Conservation of Type Material:
Type material is deposited in the mineralogical collections of the Canadian Museum of Nature, Ottawa, Canada, catalogue number CMNMC 86897, and the Natural History Museum of Los Angeles County, Los Angeles, USA, catalogue number 65618
Geological Setting of Type Material:
weathering zone of an uranium-ore deposit
Associated Minerals at Type Locality:
Synonyms of Shinkolobweite
Other Language Names for Shinkolobweite
Dutch:Shinkolobweiet
German:Shinkolobweit
Common Associates
Associations Based on Photo Data:
| 2 photos of Shinkolobweite associated with Wyartite | CaU5+(UO2)2(CO3)O4(OH) · 7H2O |
| 2 photos of Shinkolobweite associated with Schoepite | (UO2)8O2(OH)12 · 12H2O |
| 2 photos of Shinkolobweite associated with Siegenite | CoNi2S4 |
| 2 photos of Shinkolobweite associated with Uraninite | UO2 |
| 1 photo of Shinkolobweite associated with Fourmarierite | Pb(UO2)4O3(OH)4 · 4H2O |
| 1 photo of Shinkolobweite associated with Rutherfordine | (UO2)CO3 |
Related Minerals - Strunz-mindat Grouping
| 4.GB.05 | Rameauite | K2Ca(UO2)6O6(OH)4 · 6H2O |
| 4.GB.05 | Agrinierite | K2(Ca,Sr)[(UO2)3O3(OH)2]2 · 5H2O |
| 4.GB.05 | Compreignacite | K2(UO2)6O4(OH)6 · 7H2O |
| 4.GB.10 | Becquerelite | Ca(UO2)6O4(OH)6 · 8H2O |
| 4.GB.10 | Billietite | Ba(UO2)6O4(OH)6 · 4-8H2O |
| 4.GB.10 | Protasite | Ba(UO2)3O3(OH)2 · 3H2O |
| 4.GB.15 | Richetite | (Fe3+,Mg)Pb 8.6(UO2)36O36(OH)24 · 41H2O |
| 4.GB.20 | Calciouranoite | (Ca,Ba,Pb)U2O7 · 5H2O |
| 4.GB.20 | Bauranoite | Ba(UO2)2(OH)6 · 1-2H2O |
| 4.GB.20 | Metacalciouranoite | (Ca,Ba,Pb,K2)U2O7 · 2H2O |
| 4.GB.25 | Fourmarierite | Pb(UO2)4O3(OH)4 · 4H2O |
| 4.GB.30 | Wölsendorfite | Pb7(UO2)14O19(OH)4 · 12H2O |
| 4.GB.35 | Masuyite | Pb(UO2)3O3(OH)2 · 3H2O |
| 4.GB.40 | Vandendriesscheite | PbU7O22 · 12H2O |
| 4.GB.40 | Metavandendriesscheite | PbU7O22 · nH2O n < 12 |
| 4.GB.45 | Vandenbrandeite | Cu(UO2)(OH)4 |
| 4.GB.50 | Sayrite | Pb2(UO2)5O6(OH)2 · 4H2O |
| 4.GB.55 | Curite | Pb3(H2O)2[(UO2)4O4(OH)3]2 |
| 4.GB.60 | Iriginite | (UO2)Mo2O7 · 3H2O |
| 4.GB.65 | Uranosphaerite | Bi(UO2)O2(OH) |
| 4.GB.70 | Holfertite | CaxU6+2-xTi(O8-xOH4x) · 3H2O |
| 4.GB.75 | Carlosbarbosaite | (UO2)2Nb2O6(OH)2 · 2H2O |
| 4.GB.80 | Gauthierite | KPb[(UO2)7O5(OH)7] · 8H2O |
| 4.GB.85 | Kroupaite | KPb0.5[(UO2)8O4(OH)10] · 10H2O |
| 4.GB.90 | Leesite | K(H2O)2[(UO2)4O2(OH)5] · 3H2O |
| 4.GB.95 | Nollmotzite | Mg[U5+(U6+O2)2O4F3] · 4H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 66.3398% | 16,584,950 | 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 Shinkolobweite
None
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 Shinkolobweite
mindat.org URL:
https://www.mindat.org/min-51555.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Shinkolobweite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2017) New minerals and nomenclature modifications approved in 2017. CNMNC Newsletter No 36. Mineralogical Magazine, 81 (2) 403-409 doi:10.1180/minmag.2017.081.022
Olds, Travis A., Lussier, Aaron J., PetŘíček, Václav, Plášil, Jakub, Kampf, Anthony R., Oliver, Allen G., Burns, Peter C., Dembowski, Mateusz, Steele, Ian M. (2023) Shinkolobweite, from the Shinkolobwe Mine, Democratic Republic of Congo: A New Mineral Containing Uranium in the Rare Pentavalent Oxidation State. The Canadian Journal of Mineralogy and Petrology, 61 (5) 999-1020 doi:10.3749/2300003
Localities for Shinkolobweite
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) | |
| Mineralogical Magazine +1 other reference |
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Shinkolobwe Mine, Shinkolobwe, Kambove Territory, Haut-Katanga, DR Congo