Phuralumite
A valid IMA mineral species
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About Phuralumite
Formula:
Al2[(UO2)3(PO4)2O(OH)](OH)3(H2O)9
Colour:
Lemon yellow
Hardness:
3
Specific Gravity:
3.383 (Calculated)
Crystal System:
Monoclinic
Member of:
Name:
For the PHosphate, URanyl and ALUMinium ions in its composition.
Type Locality:
This page provides mineralogical data about Phuralumite.
Unique Identifiers
Mindat ID:
3201
Long-form identifier:
mindat:1:1:3201:4
Classification of Phuralumite
Phosphuranylite sheet topology
The sheet topology exhibited by members of the phosphuranylite group.
IMA Classification of Phuralumite
Approved
IMA Formula:
Al2[(U6+O2)3(PO4)2O(OH)](OH)3(H2O)9
Approval year:
1978
First published:
1979
Type description reference:
8.EC.05
8 : PHOSPHATES, ARSENATES, VANADATES
E : Uranyl phosphates and arsenates
C : UO2:RO4 = 3:2
8 : PHOSPHATES, ARSENATES, VANADATES
E : Uranyl phosphates and arsenates
C : UO2:RO4 = 3:2
42.4.6.1
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
4 : (AB)5(XO4)2Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
4 : (AB)5(XO4)2Zq·xH2O
19.11.29
19 : Phosphates
11 : Phosphates of U
19 : Phosphates
11 : Phosphates of U
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 |
|---|---|---|
| Pha | 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 Phuralumite
Transparency:
Translucent
Colour:
Lemon yellow
Hardness:
3 on Mohs scale
Cleavage:
Perfect
On {010}
On {010}
Density:
3.383(10) g/cm3 (Calculated)
Optical Data of Phuralumite
Type:
Biaxial (-)
RI values:
nα = 1.559 nβ = 1.616 nγ = 1.624
2V:
Measured: 40° , Calculated: 38°
Max. Birefringence:
δ = 0.065
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:
r < v moderate
Pleochroism:
Weak
Comments:
Colorless to very pale yellow on Y and Z
Comments:
X = b, Y near elongation
Chemistry of Phuralumite
Mindat Formula:
Al2[(UO2)3(PO4)2O(OH)](OH)3(H2O)9
Element Weights:
Crystallography of Phuralumite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 9.4407(3) Å, b = 20.8596(8) Å, c = 13.4326(4) Å
β = 107.905(4)°
β = 107.905(4)°
Ratio:
a:b:c = 0.453 : 1 : 0.644
Unit Cell V:
2517.4 ų
Z:
4
Comment:
Space-group setting P21/n. Date from et al. (2017). Cell of type material was given as a = 13.87, b = 20.79 Å, c = 9.38, β = 112°.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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Big Balls | Small Balls | Just Balls | Spacefill
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CIF File Best | x | y | z | a | b | c
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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) |
|---|---|---|---|---|---|---|---|
| 0009687 | Phuralumite | Piret P, Piret-Meunier J, Declercq J P (1979) Structure of phuralumite Acta Crystallographica B35 1880-1882 |  | 1979 | Kobokobo, Kivu, Zaire | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.4 Å | (100) |
| 6.03 Å | (50) |
| 4.24 Å | (60) |
| 4.18 Å | (80) |
| 3.43 Å | (80) |
| 3.17 Å | (70) |
| 3.084 Å | (70) |
| 2.903 Å | (75) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Type Occurrence of Phuralumite
General Appearance of Type Material:
Lemon-yellow prismatic crystals, to 0.5 mm
Place of Conservation of Type Material:
Royal Museum of Central Africa, Tervuren, Belgium.
Geological Setting of Type Material:
beryl-columbite pegmatite
Associated Minerals at Type Locality:
Synonyms of Phuralumite
Other Language Names for Phuralumite
Relationship of Phuralumite to other Species
Member of:
Other Members of Phosphuranylite Group:
| Althupite | AlTh(UO2)7(PO4)4(OH)5O2 · 15H2O | Tric. 1 : P1 |
| Bergenite | Ca2Ba4(UO2)9(PO4)6O6 · 16H2O | Mon. 2/m : P21/b |
| Dewindtite | H2Pb3(UO2)6O4(PO4)4 · 12H2O | Orth. mmm(2/m2/m2/m) : Cmma |
| Dumontite | Pb2(UO2)3O2(PO4)2 · 5H2O | Mon. 2/m : P21/m |
| Françoisite-(Ce) | (Ce,Nd,Ca)(UO2)3(PO4)2O(OH) · 6H2O | Mon. 2/m : P21/b |
| Françoisite-(Nd) | (Nd,Ce,Sm)(UO2)3(PO4)2O(OH) · 6H2O | Mon. 2/m |
| Hügelite | Pb2(UO2)3(AsO4)2O2 · 5H2O | Mon. 2/m : P21/m |
| Phosphuranylite | KCa(H3O)3(UO2)7(PO4)4O4 · 8H2O | Orth. mmm(2/m2/m2/m) : Cmcm |
| Phurcalite | Ca2(UO2)3(PO4)2O2 · 7H2O | Orth. mmm(2/m2/m2/m) : Pbca |
| Upalite | Al(UO2)3(PO4)2O(OH) · 7H2O | Mon. 2/m : P21/b |
| Vanmeersscheite | U6+(UO2)3(PO4)2(OH)6 · 4H2O | Orth. mmm(2/m2/m2/m) |
| Yingjiangite | K2Ca(UO2)7(PO4)4(OH)6 · 6H2O | Orth. mmm(2/m2/m2/m) : Cmcm |
Common Associates
Associations Based on Photo Data:
| 2 photos of Phuralumite associated with Microcline | K(AlSi3O8) |
| 2 photos of Phuralumite associated with Eylettersite | Th0.75Al3(PO4)2(OH)6 |
| 1 photo of Phuralumite associated with Ranunculite | HAl(UO2)(PO4)(OH)3 · 4H2O |
| 1 photo of Phuralumite associated with Quartz | SiO2 |
Related Minerals - Strunz-mindat Grouping
| 8.EC.05 | Upalite | Al(UO2)3(PO4)2O(OH) · 7H2O |
| 8.EC.05 | Françoisite-(Nd) | (Nd,Ce,Sm)(UO2)3(PO4)2O(OH) · 6H2O |
| 8.EC.05 | Françoisite-(Ce) | (Ce,Nd,Ca)(UO2)3(PO4)2O(OH) · 6H2O |
| 8.EC.10 | Yingjiangite | K2Ca(UO2)7(PO4)4(OH)6 · 6H2O |
| 8.EC.10 | Renardite | Pb(UO2)4(PO4)2(OH)4 · H2O |
| 8.EC.10 | Phosphuranylite | KCa(H3O)3(UO2)7(PO4)4O4 · 8H2O |
| 8.EC.10 | Arsenuranylite | Ca(UO2)4(AsO4)2(OH)4 · 6H2O |
| 8.EC.10 | 'Kivuite' | Th(UO2)4(PO3OH)2(OH)8 · 7H2O |
| 8.EC.10 | Dewindtite | H2Pb3(UO2)6O4(PO4)4 · 12H2O |
| 8.EC.15 | Dumontite | Pb2(UO2)3O2(PO4)2 · 5H2O |
| 8.EC.15 | Hügelite | Pb2(UO2)3(AsO4)2O2 · 5H2O |
| 8.EC.20 | Vanmeersscheite | U6+(UO2)3(PO4)2(OH)6 · 4H2O |
| 8.EC.20 | Arsenovanmeersscheite | U6+(UO2)3(AsO4)2(OH)6 · 4H2O |
| 8.EC.20 | Metavanmeersscheite | U6+(UO2)3(PO4)2(OH)6 · 2H2O |
| 8.EC.25 | Althupite | AlTh(UO2)7(PO4)4(OH)5O2 · 15H2O |
| 8.EC.30 | Mundite | Al(UO2)3(PO4)2(OH)3 · 5.5H2O |
| 8.EC.35 | Phurcalite | Ca2(UO2)3(PO4)2O2 · 7H2O |
| 8.EC.40 | Bergenite | Ca2Ba4(UO2)9(PO4)6O6 · 16H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 54.9232% | 13,730,800 | 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 Phuralumite
Phuralumite is not fluorescent in UV, however, it is often associated with nearly identical looking minerals which are variously fluorescent in UV, usually in various shades of yellow to greenish yellow.
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 Phuralumite
mindat.org URL:
https://www.mindat.org/min-3201.html
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References for Phuralumite
Reference List:
Deliens, Michel, Piret, Paul (1979) Les phosphates d'uranyle et d'aluminium de Kobokobo. II. La phuralumite Al2(UO2)3(PO4)2(OH)6·10H2O et l'upalite Al(UO2)3(PO4)2(OH)3, nouveaux minéraux. Bulletin de Minéralogie, 102 (4) 333-337 doi:10.3406/bulmi.1979.7326
Piret, P., Piret-Meunier, J., Declercq, J. P. (1979) Structure of phuralumite. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 35 (8) 1880-1882 doi:10.1107/s0567740879007950
Deliens, Michel, Piret, Paul (1979) Les phosphates d'uranyle et d'aluminium de Kobokobo. II. La phuralumite Al2(UO2)3(PO4)2(OH)6·10H2O et l'upalite Al(UO2)3(PO4)2(OH)3, nouveaux minéraux. Bulletin de Minéralogie, 102 (4) 333-337 doi:10.3406/bulmi.1979.7326
Fleischer, M.; Mandarino, J.A.; Pabst, A. (1980) New mineral names. American Mineralogist, 65 (1-2). 205-210
Localities for Phuralumite
Showing 3 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) | |
| Deliens et al. (1979) |
Spain | |
| www.foro-minerales.com (n.d.) |
Switzerland | |
| Stalder et al. (1998) |
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Kobokobo pegmatite, Mwenga Territory, South Kivu, DR Congo