Sabugalite
A valid IMA mineral species - grandfathered
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About Sabugalite
Sabugal, Portugal
Formula:
HAl(UO2)4(PO4)4 · 16H2O
Colour:
Yellow
Lustre:
Resinous, Waxy, Greasy
Hardness:
2½
Specific Gravity:
3.20
Crystal System:
Monoclinic
Member of:
Name:
Named in 1951 by Clifford Frondel for the town of Sabugal, Portugal, near the type locality of the Bica Mine.
An aluminum phosphate member of the autunite group.
Note: most of the photos shown here do not seem to show reliably confirmed sabugalite (see discussion in https://www.mindat.org/mesg-7-371177.html).
A hypothetical As analogue is Paulite (of Bültemann).
Note: most of the photos shown here do not seem to show reliably confirmed sabugalite (see discussion in https://www.mindat.org/mesg-7-371177.html).
A hypothetical As analogue is Paulite (of Bültemann).
Unique Identifiers
Mindat ID:
3496
Long-form identifier:
mindat:1:1:3496:4
Classification of Sabugalite
The autunite-type sheet
The autunite-type sheet found in members of the autunite group.
IMA Classification of Sabugalite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
HAl(U6+O2)4(PO4)4·16H2O
First published:
1951
Type description reference:
8.EB.55
8 : PHOSPHATES, ARSENATES, VANADATES
E : Uranyl phosphates and arsenates
B : UO2:RO4 = 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
E : Uranyl phosphates and arsenates
B : UO2:RO4 = 1:1
40.2a.24.1
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
2a : AB2(XO4)2·xH2O, containing (UO2)2+
40 : HYDRATED NORMAL PHOSPHATES,ARSENATES AND VANADATES
2a : AB2(XO4)2·xH2O, containing (UO2)2+
19.11.31
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 |
|---|---|---|
| Sbg | 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 Sabugalite
Resinous, Waxy, Greasy
Transparency:
Transparent, Translucent
Colour:
Yellow
Hardness:
2½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
{001}
{001}
Fracture:
Micaceous
Comment:
Somewhat flexible.
Density:
3.20 g/cm3 (Measured) 3.150 g/cm3 (Calculated)
Optical Data of Sabugalite
Type:
Biaxial (-)
RI values:
nα = 1.564 - 1.565 nβ = 1.581 - 1.583 nγ = 1.582 - 1.584
Birefringence:
0.018
Max. Birefringence:
δ = 0.018 - 0.019
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.
No measured or calculated 2V is on file for this mineral, so the value used here (27°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
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.
No measured or calculated 2V is on file for this mineral, so the value used here (27°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
r > v strong
Optical Extinction:
Plates ordinarily extinguish uniformly; sometimes showing mottled extinction.
Pleochroism:
Visible
Comments:
X = colorless; Y = Z = pale yellow.
Chemistry of Sabugalite
Mindat Formula:
HAl(UO2)4(PO4)4 · 16H2O
Element Weights:
Crystallography of Sabugalite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 19.426 Å, b = 9.483 Å, c = 9.850 Å
β = 96.16°
β = 96.16°
Ratio:
a:b:c = 2.049 : 1 : 1.039
Unit Cell V:
1,804.06 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Thin square or lath-like crystals dominated by {001}, that is uneven or warped. Other forms are narrow {100} and {h0l}, and rare 45° corner truncations by {hkl}. Crystals commonly in subparallel growths joined on {001}.
Comment:
data on synthetic material
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.69 Å | (100) |
| 4.86 Å | (90) |
| 4.39 Å | (40) |
| 3.47 Å | (80) |
| 2.452 Å | (20) |
| 2.389 Å | (20) |
| 2.188 Å | (60) |
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 Sabugalite
General Appearance of Type Material:
Densely aggregated crusts of very thin platy yellow crystals and scales up to about one millimeter on edge.
Place of Conservation of Type Material:
The Natural History Museum, London, England, number 1958,733.
Harvard University, Cambridge, Massachusetts, numbers 102192, 102193.
National Museum of Natural History, Washington, D.C., USA, numbers 106335–106337.
Harvard University, Cambridge, Massachusetts, numbers 102192, 102193.
National Museum of Natural History, Washington, D.C., USA, numbers 106335–106337.
Geological Setting of Type Material:
A secondary mineral in uranium deposits.
Associated Minerals at Type Locality:
Synonyms of Sabugalite
Other Language Names for Sabugalite
Relationship of Sabugalite to other Species
Member of:
Other Members of Autunite Group:
| Autunite | Ca(UO2)2(PO4)2 · 10-12H2O | Orth. mmm(2/m2/m2/m) : Pnma |
| Bassetite | Fe2+(UO2)2(PO4)2 · 10H2O | Mon. 2/m |
| Heinrichite | Ba(UO2)2(AsO4)2 · 10H2O | Mon. 2/m : P2/b |
| Hydronováčekite | Mg(UO2)2(AsO4)2 · 12H2O | Tric. 1 : P1 |
| Kahlerite | Fe2+(UO2)2(AsO4)2 · 12H2O | Tet. 4/m : P42/n |
| Nováčekite | Mg(UO2)2(AsO4)2 · 10H2O | Mon. 2/m |
| Rauchite | Ni(UO2)2(AsO4)2 · 10H2O | Tric. 1 : P1 |
| Saléeite | Mg(UO2)2(PO4)2 · 10H2O | Mon. 2/m |
| Torbernite | Cu(UO2)2(PO4)2 · 12H2O | Tet. 4/mmm(4/m2/m2/m) : I4/mmm |
| Uranocircite | Ba(UO2)2(PO4)2 · 10H2O | Tet. |
| Uranospinite | Ca(UO2)2(AsO4)2 · 10H2O | Tet. 4/mmm(4/m2/m2/m) : P4/nmm |
| Zeunerite | Cu(UO2)2(AsO4)2 · 12H2O | Tet. 4/mmm(4/m2/m2/m) : I4/mmm |
Common Associates
Associations Based on Photo Data:
| 11 photos of Sabugalite associated with Autunite | Ca(UO2)2(PO4)2 · 10-12H2O |
| 10 photos of Sabugalite associated with Torbernite | Cu(UO2)2(PO4)2 · 12H2O |
| 2 photos of Sabugalite associated with Phosphuranylite | KCa(H3O)3(UO2)7(PO4)4O4 · 8H2O |
| 1 photo of Sabugalite associated with Metatorbernite | Cu(UO2)2(PO4)2 · 8H2O |
| 1 photo of Sabugalite associated with Meta-autunite | Ca(UO2)2(PO4)2 · 6H2O |
| 1 photo of Sabugalite associated with Carnotite | K2(UO2)2(VO4)2 · 3H2O |
| 1 photo of Sabugalite associated with 'Pitchblende' | UO2 |
| 1 photo of Sabugalite associated with Curienite | Pb(UO2)2(VO4)2 · 5H2O |
Related Minerals - Strunz-mindat Grouping
| 8.EB. | Meta-autunite Group | A1-2(UO2)2(TO4)2 · 5-10H2O |
| 8.EB.05 | Rauchite | Ni(UO2)2(AsO4)2 · 10H2O |
| 8.EB.05 | Uranocircite | Ba(UO2)2(PO4)2 · 10H2O |
| 8.EB.05 | Uranospinite | Ca(UO2)2(AsO4)2 · 10H2O |
| 8.EB.05 | Zeunerite | Cu(UO2)2(AsO4)2 · 12H2O |
| 8.EB.05 | Metarauchite | Ni(UO2)2(AsO4)2 · 8H2O |
| 8.EB.05 | Heinrichite | Ba(UO2)2(AsO4)2 · 10H2O |
| 8.EB.05 | Kahlerite | Fe2+(UO2)2(AsO4)2 · 12H2O |
| 8.EB.05 | Hydronováčekite | Mg(UO2)2(AsO4)2 · 12H2O |
| 8.EB.05 | Torbernite | Cu(UO2)2(PO4)2 · 12H2O |
| 8.EB.05 | Nováčekite | Mg(UO2)2(AsO4)2 · 10H2O |
| 8.EB.05 | Autunite | Ca(UO2)2(PO4)2 · 10-12H2O |
| 8.EB.05 | Saléeite | Mg(UO2)2(PO4)2 · 10H2O |
| 8.EB.05 | Xiangjiangite | (Fe3+,Al)(UO2)4(PO4)2(SO4)2(OH) · 22H2O |
| 8.EB.10 | Bassetite | Fe2+(UO2)2(PO4)2 · 10H2O |
| 8.EB.10 | Lehnerite | Mn2+(UO2)2(PO4)2 · 8H2O |
| 8.EB.10 | Meta-autunite | Ca(UO2)2(PO4)2 · 6H2O |
| 8.EB.10 | Metasaléeite | Mg(UO2)2(PO4)2 · 8H2O |
| 8.EB.10 | Metauranocircite | Ba(UO2)2(PO4)2 · 7H2O |
| 8.EB.10 | Metauranospinite | Ca(UO2)2(AsO4)2 · 8H2O |
| 8.EB.10 | Metaheinrichite | Ba(UO2)2(AsO4)2 · 8H2O |
| 8.EB.10 | Metakahlerite | Fe2+(UO2)2(AsO4)2 · 8H2O |
| 8.EB.10 | Metakirchheimerite | Co(UO2)2(AsO4)2 · 8H2O |
| 8.EB.10 | Metanováčekite | Mg(UO2)2(AsO4)2 · 8H2O |
| 8.EB.10 | Metanatroautunite | Na(UO2)(PO4)(H2O)3 |
| 8.EB.10 | Metatorbernite | Cu(UO2)2(PO4)2 · 8H2O |
| 8.EB.10 | Metazeunerite | Cu(UO2)2(AsO4)2 · 8H2O |
| 8.EB.10 | Przhevalskite | Pb2(UO2)3(PO4)2(OH)4 · 3H2O |
| 8.EB.10 | 'Pseudo-autunite' | (H3O)4Ca2(UO2)2(PO4)4 · 5H2O |
| 8.EB.15 | Abernathyite | K(UO2)(AsO4) · 3H2O |
| 8.EB.15 | Uramphite | (NH4)2(UO2)2(PO4)2 · 6H2O |
| 8.EB.15 | Meta-ankoleite | K2(UO2)2(PO4)2 · 6H2O |
| 8.EB.15 | Natrouranospinite | Na2(UO2)2(AsO4)2 · 5H2O |
| 8.EB.15 | Trögerite | (H3O)(UO2)(AsO4) · 3H2O |
| 8.EB.15 | Chernikovite | (H3O)2(UO2)2(PO4)2 · 6H2O |
| 8.EB.15 | Uramarsite | (NH4)(UO2)(AsO4) · 3H2O |
| 8.EB.20 | Chistyakovaite | Al(UO2)2(AsO4)2(F,OH) · 6.5H2O |
| 8.EB.20 | Threadgoldite | Al(UO2)2(PO4)2(OH) · 8H2O |
| 8.EB.25 | Uranospathite | (Al,◻)(UO2)2(PO4)2F · 20(H2O,F) |
| 8.EB.25 | Arsenuranospathite | Al(UO2)2(AsO4)2F · 20H2O |
| 8.EB.30 | Vochtenite | (Fe2+,Mg)Fe3+(UO2)4(PO4)4(OH) · 12-13H2O |
| 8.EB.35 | Coconinoite | Fe3+2Al2(UO2)2(PO4)4(SO4)(OH)2 · 20H2O |
| 8.EB.40 | Ranunculite | HAl(UO2)(PO4)(OH)3 · 4H2O |
| 8.EB.45 | Triangulite | Al3(UO2)4(PO4)4(OH)5 · 5H2O |
| 8.EB.50 | Furongite | Al13(UO2)7(PO4)13(OH)14 · 58H2O |
| 8.EB.55 | Arsenosabugalite | H0.5Al0.5(UO2)2(AsO4)2 · 8H2O |
| 8.EB.60 | Horákite | (Bi7O7OH)[(UO2)4(PO4)2(AsO4)2(OH)2] · 3.5H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 53.6032% | 13,400,800 | 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 Sabugalite
Fluoresces bright lemon yellow in both SW and LW.
Other Information
Thermal Behaviour:
The temperature of breakdown of the fully-hydrated to the meta-II phase is between 68° and 101°.
Notes:
Radioactive.
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 Sabugalite
mindat.org URL:
https://www.mindat.org/min-3496.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 Sabugalite
Reference List:
Frondel, Clifford (1951) Studies of uranium minerals (VIII): Sabugalite, an aluminum-autunite. American Mineralogist, 36 (9-10) 671-679
Localities for Sabugalite
Showing 108 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.
African Plate | |
| Badahmaoui et al. (2020) |
Algeria | |
| MEKTI et al. (2025) |
Australia | |
| Jacobson et al. (2007) |
Belgium | |
| Dejonghe et al. (1982) +1 other reference |
Brazil | |
| Cassedanne (1983) +1 other reference |
| Cassedanne et al. (1999) |
Bulgaria | |
| Kalaidjiev et al. (2009) |
Canada | |
| Peatfield (n.d.) |
China | |
| Anthony |
Czech Republic | |
| Č +4 other references |
France | |
| - (1998) |
| - (1998) |
| - (1998) |
| R. Pierrot |
| R. Pierrot | |
| - (1998) |
| - (1998) | |
| R. Pierrot |
| R. Pierrot |
| R. Pierrot |
| R. Pierrot |
| Wittern et al. (1997) |
| |
| Lièvre et al. (2002) |
| Lièvre et al. (2002) |
| Lièvre et al. (2002) |
| Bariand et al. (n.d.) |
| Patrice Queneau Collection visual identification. Confirmed. Analyzed by Nicolas Meisser (Naturéum) | |
| - (1998) | |
| - (1998) | |
| - (1998) | |
| - (1998) |
| R. Pierrot |
| Christophe Boutry collection |
| - (1998) |
| J. Geffroy |
| - (1998) |
| - (1998) |
Germany | |
| Weiß (1990) |
| Weiß (1990) |
| Weiß (1990) | |
Italy | |
| Vignola et al. (2011) |
| Stara (1990) |
| Garavelli et al. (1959) +2 other references | |
| Ref: Daniele Ravagnani - I giacimenti ... +1 other reference |
| Campostrini et al. (2006) |
Japan | |
| K. Watanabe (1976) |
Poland | |
| Lis et al. (1986) |
| Lis et al. (1986) | |
| Domańska-Siuda J. 2010: New data on secondary uranium minerals from the Western Sudetes (Poland) +2 other references |
Portugal | |
| LNEG - Laboratório Nacional de Energia ... |
| LNEG/Siorminp | |
| |
| |
| nautilus.fis.uc.pt (n.d.) |
| LNEG - Laboratório Nacional de Energia ... |
| Schnorrer-Köhler et al. (1991) |
| Frondel (1951) |
| LNEG |
| LNEG/Siorminp database |
| LNEG/Siorminp database |
| C. F. Torre de Assunção- Sobre as ... |
| |
| |
| LNEG - Laboratório Nacional de Energia ... |
Slovakia | |
| Kopáčik R. (2017) |
| Martin Števko |
| Števko M. (2022) |
South Africa | |
| Cairncross et al. (1995) |
Spain | |
| - (1994) |
| www.foro-minerales.com (n.d.) |
| www.foro-minerales.com (n.d.) | |
| D Respino collection | |
| A. M. I. Martins collection +1 other reference |
| Calvo Rebollar (2015) |
| www.foro-minerales.com (n.d.) |
UK | |
| Darnley et al. (1965) |
USA | |
| Anthony et al. (1995) |
| Bollin et al. (1958) |
| Holland et al. (1958) +2 other references |
| Holland et al. (1958) +2 other references | |
| Holland et al. (1958) +2 other references | |
| Scarborough (1981) |
| Holland et al. (1958) +2 other references | |
| Scarborough (1981) | |
| Holland et al. (1958) +2 other references | |
| Murdoch et al. (1966) |
| Eckel et al. (1997) |
| Eckel et al. (1997) |
| Eckel et al. (1997) |
| Pabian (1971) |
| Castor et al. (2004) |
| Castor et al. (2004) |
| Castor et al. (2004) |
| NBMG Bull 70 Geology and Mineral ... +3 other references | |
| Northrop et al. (1996) |
| Caldwell (2018) | |
| NMBMMR Memoir 15 Geology and Technology ... +1 other reference | |
| Northrop et al. (1996) |
| Page et al. (1956) +3 other references | |
| Nevada Bureau of Mines and Geology NBMG ... |
| Bullock (1981) |
| Kampf et al. (2018) |
| USGS TEI #514 +1 other reference |
| USGS MRDS Database |
| Page et al. (1956) +2 other references |
Quick NavTopAbout SabugaliteUnique IdentifiersClassification IMA Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatRadioactivityFluorescence Other InformationInternet Links References Localities Locality List
Skalka uranium occurrence, Brezno, Brezno District, Banská Bystrica Region, Slovakia