Shumwayite
A valid IMA mineral species
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About Shumwayite
Formula:
(UO2)2(SO4)2 · 5H2O
Structural formula: [(UO2)(SO4)(H2O)2]2·5H2O
Colour:
Pale greenish-yellow
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
3.844 (Calculated)
Crystal System:
Monoclinic
Name:
For the Shumway family, whose members are connected with the discovery and exploitation of many uranium deposits of the Colorado Plateau, including that within the Green Lizard mine. Family members account for the discovery and mining of hundreds of uranium deposits on the Colorado Plateau. Arah E. Shumway (1891-1968) prospected Red Canyon during the 1920’s and was one of the first to stake mining claims and mine for uranium. Dan Shumway (b. 1946) was one of the claim stakers for the Green Lizard mine at which shumwayite was first recognized. Dr. Gary L. Shumway (b. 1938), Professor Emeritus of history at the University of California, Fullerton, is well-known for his research and publications on uranium mining and exploration.
New structure type.
One of the most simple uranyl sulfate minerals to date. Chemically similar (although basic) minerals are jáchymovite, uranopilite, metauranopilite.
Crystal structure details: (1) UO7 pentagonal bipyramids (2) SO4 tetrahedra; (3) U- and S-centred polyhedra share corners to form [(UO2)(SO4)(H2O)2] chains along [100]; (4) hydrogen bonds stand for an exclusive link for isolated intra-chain water molecules and the chains.
One of the most simple uranyl sulfate minerals to date. Chemically similar (although basic) minerals are jáchymovite, uranopilite, metauranopilite.
Crystal structure details: (1) UO7 pentagonal bipyramids (2) SO4 tetrahedra; (3) U- and S-centred polyhedra share corners to form [(UO2)(SO4)(H2O)2] chains along [100]; (4) hydrogen bonds stand for an exclusive link for isolated intra-chain water molecules and the chains.
Unique Identifiers
Mindat ID:
46824
Long-form identifier:
mindat:1:1:46824:6
IMA Classification of Shumwayite
Classification of Shumwayite
7.EA.15
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
E : Uranyl sulfates
A : Without cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
E : Uranyl sulfates
A : Without 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 |
|---|---|---|
| Smw | 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 Shumwayite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Pale greenish-yellow
Streak:
White
Hardness:
2 on Mohs scale
Comment:
ca. 2
Tenacity:
Brittle
Cleavage:
Perfect
{011}
{011}
Fracture:
Irregular/Uneven
Density:
3.844 g/cm3 (Calculated)
Optical Data of Shumwayite
Type:
Biaxial (+/-)
RI values:
nα = 1.581(1) nβ = 1.588(1) nγ = 1.595(1)
2V:
Measured: 89.8° (8), Calculated: 89.6°
Max. Birefringence:
δ = 0.014
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 (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:
strong (sense couldn't be defined due to ambiguous sign)
Pleochroism:
Non-pleochroic
Comments:
Orientation: X=b, Y≈c, Z≈a
Chemistry of Shumwayite
Mindat Formula:
(UO2)2(SO4)2 · 5H2O
Structural formula: [(UO2)(SO4)(H2O)2]2·5H2O
Structural formula: [(UO2)(SO4)(H2O)2]2·5H2O
Element Weights:
Elements listed:
Crystallography of Shumwayite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/c
Cell Parameters:
a = 6.7475(1) Å, b = 12.5026(3) Å, c = 16.903(1) Å
β = 90.919(6)°
β = 90.919(6)°
Ratio:
a:b:c = 0.54 : 1 : 1.352
Unit Cell V:
1425.79 ų
Z:
4
Morphology:
prismatic crystals
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 6.97 Å | (39) |
| 5.58 Å | (48) |
| 5.11 Å | (100) |
| 4.86 Å | (44) |
| 4.40 Å | (38) |
| 4.04 Å | (47) |
| 3.459 Å | (42) |
| 3.373 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47b : [Sulfates and sulfites] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Geological Setting:
Green Lizard mine
Type Occurrence of Shumwayite
Co-Type Localities:
General Appearance of Type Material:
prisms, up to about 0.3 mm, [100] elongation; often in subparallel to random intergrowths
Place of Conservation of Type Material:
Cotype material is deposited in the mineralogical collections of the Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA, catalogue numbers 65589 and 65590 (GLM), 65591 and 65592 (GSM), and the Fersman Minera
Geological Setting of Type Material:
secondary (alteration) mineral
Associated Minerals at Type Locality:
Synonyms of Shumwayite
Other Language Names for Shumwayite
Dutch:Shumwayiet
German:Shumwayit
Common Associates
Associations Based on Photo Data:
| 1 photo of Shumwayite associated with 'Asphaltite' |
Related Minerals - Strunz-mindat Grouping
| 7.EA. | Scenicite | [(UO2)(H2O)2(SO4)]2 · 3H2O |
| 7.EA.05 | Uranopilite | (UO2)6(SO4)O2(OH)6 · 14H2O |
| 7.EA.05 | Metauranopilite | (UO2)6(SO4)(OH)10 · 5H2O |
| 7.EA.10 | Jáchymovite | (UO2)8(SO4)(OH)14 · 13H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 57.8965% | 14,474,125 | 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 Shumwayite
bright greenish white (LW & SW) - Only Utah specimens; may be quenched by Fe,Zn contents
Other Information
Notes:
slightly deliquescent; easily soluble 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 Shumwayite
mindat.org URL:
https://www.mindat.org/min-46824.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 Shumwayite
Reference List:
Hålenius, U.; Hatert, F.; Pasero, M.; Mills, S. J. (2015) New minerals and nomenclature modifications approved in 2015. Mineralogical Magazine, 79 (5). p.1223-1230. doi:10.1180/minmag.2015.079.5.16
Kampf, Anthony R., Plášil, Jakub, Kasatkin, Anatoly V., Marty, Joe, Čejka, Jiří, Lapčák, Ladislav (2017) Shumwayite, [(UO2)(SO4)(H2O)2]2·H2O, a new uranyl sulfate mineral from Red Canyon, San Juan County, Utah, USA. Mineralogical Magazine, 81 (2) 273-285 doi:10.1180/minmag.2016.080.091
Kornyakov, Ilya V.; Samarkina, Nastasia K.; Izatulina, Alina R.; Krzhizhanovskaya, Maria G.; Krivovichev, Sergey V.; Gurzhiy, Vladislav V. (2025) High-temperature powder versus single-crystal X-ray diffraction studies: which method to choose? Thermal behavior of shumwayite, [(UO2)(SO4)(H2O)2]2·H2O. Journal of Applied Crystallography, 58 (5). 1615-1626 doi:10.1107/s160057672500651x
Localities for Shumwayite
Showing 5 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.
Czech Republic | |
| Sejkora et al. (2019) |
USA | |
| Travis Olds collection |
| Hålenius et al. (2015) +1 other reference |
| Hålenius et al. (2015) +2 other references |
| Kampf et al. (2023) |
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Giveway-Simplot Mine, Red Canyon Mining District, San Juan County, Utah, USA