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Carlosbarbosaite
A valid IMA mineral species
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About Carlosbarbosaite
Formula:
(UO2)2Nb2O6(OH)2 · 2H2O
Generally contains some Ca and Si; formula also given as (Ca0.5□0.5)(UO2)2(Nb5+Si)O6(OH)2.2H2O
Colour:
Cream to pale yellow
Lustre:
Vitreous
Specific Gravity:
4,713 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honour of Carlos do Prado Barbosa (7 January 1917, Alfenas, Minas Gerais, Brazil - 7 April 2003), chemical engineer, mineralogist, and mineral dealer. In his early career, he worked at the National Institute of Technology in Rio de Janeiro, Brazil. As a dealer, he was known for bringing many rare and unusual species to market. He was a co-author of the descriptions of bahianite and minasgeraisite-(Y).
Type Locality:
Unique Identifiers
Mindat ID:
41099
Long-form identifier:
mindat:1:1:41099:3
IMA Classification of Carlosbarbosaite
Approved
IMA Formula:
(U6+O2)2Nb5+2O6(OH)2·2H2O
Approval year:
2010
First published:
2012
Type description reference:
Atencio, D., Roberts, A. C., Cooper, M. A., Filho, L. A. D. Menezes, Coutinho, J. M. V., Stirling, J. A. R., Venance, K. E., Ball, N. A., Moffatt, E., Chaves, M. L. S. C., Brandão, P. R. G., Romano, A. W. (2012) Carlosbarbosaite, ideally (UO2)2Nb2O6(OH)2·2H2O, a new hydrated uranyl niobate mineral with tunnels from Jaguaraçu, Minas Gerais, Brazil: description and crystal structure. Mineralogical Magazine, 76 (1) 75-90 doi:10.1180/minmag.2012.076.1.75
Classification of Carlosbarbosaite
4.GB.75
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 |
|---|---|---|
| Cbb | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Carlosbarbosaite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Carlosbarbosaite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Cream to pale yellow
Streak:
Yellowish white
Density:
4,713 g/cm3 (Calculated)
Comment:
D(calc): 4.713-4.712
Chemistry of Carlosbarbosaite
Mindat Formula:
(UO2)2Nb2O6(OH)2 · 2H2O
Generally contains some Ca and Si; formula also given as (Ca0.5□0.5)(UO2)2(Nb5+Si)O6(OH)2.2H2O
Generally contains some Ca and Si; formula also given as (Ca0.5□0.5)(UO2)2(Nb5+Si)O6(OH)2.2H2O
Element Weights:
Elements listed:
Crystallography of Carlosbarbosaite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Cmcm
Cell Parameters:
a = 14.150(6) Å, b = 10.395(4) Å, c = 7.529(3) Å
Ratio:
a:b:c = 1.361 : 1 : 0.724
Unit Cell V:
1,107.43 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.405 Å | (80) |
| 7.081 Å | (100) |
| 4.201 Å | (90) |
| 3.333 Å | (60) |
| 3.053 Å | (80) |
| 2.931 Å | (70) |
| 2.803 Å | (60) |
| 2.589 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Type Occurrence of Carlosbarbosaite
General Appearance of Type Material:
Long flattened lath-like crystals with a very simple orthorhombic morphology. The crystals are elongated along [001], flattened on (100) and up to 120 μm long and 2–5 μm thick.
Place of Conservation of Type Material:
Museu de Geociencias, Instituto de Geociencias, Universidade de Sao Paulo, Rua do Lago, 562, 05508-080 Sao Paulo, Brazil, number DR707.
Microgram portions are housed in the Systematic Reference Series of the National Mineral Collection at the Geologica
Microgram portions are housed in the Systematic Reference Series of the National Mineral Collection at the Geologica
Reference:
Atencio, D., Roberts, A. C., Cooper, M. A., Filho, L. A. D. Menezes, Coutinho, J. M. V., Stirling, J. A. R., Venance, K. E., Ball, N. A., Moffatt, E., Chaves, M. L. S. C., Brandão, P. R. G., Romano, A. W. (2012) Carlosbarbosaite, ideally (UO2)2Nb2O6(OH)2·2H2O, a new hydrated uranyl niobate mineral with tunnels from Jaguaraçu, Minas Gerais, Brazil: description and crystal structure. Mineralogical Magazine, 76 (1) 75-90 doi:10.1180/minmag.2012.076.1.75
Synonyms of Carlosbarbosaite
Other Language Names for Carlosbarbosaite
Dutch:Carlosbarbosaiet
German:Carlosbarbosait
Common Associates
Associations Based on Photo Data:
| 2 photos of Carlosbarbosaite associated with 'Columbite-(Fe)-Columbite-(Mn) Series' |
Related Minerals - Strunz-mindat Grouping
| 4.GB. | Leishmanite | Ba(H2O)4[(UO2)3O2(OH)3]2 · 3H2O |
| 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.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 | Shinkolobweite | Pb1.333[U5+O(OH)(UO2)5O4.67(OH)5.33](H2O)5 |
| 4.GB.95 | Nollmotzite | Mg[U5+(U6+O2)2O4F3] · 4H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 53.3751% | 13,343,775 | 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 Carlosbarbosaite
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 Carlosbarbosaite
mindat.org URL:
https://www.mindat.org/min-41099.html
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External Links:
Mineral Dealers:
References for Carlosbarbosaite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2011) New minerals and nomenclature modifications approved in 2010, CNMNC Newsletter No 7. Mineralogical Magazine, 75 (1) 27-31 doi:10.1180/minmag.2011.075.1.27
Atencio, D., Roberts, A. C., Cooper, M. A., Filho, L. A. D. Menezes, Coutinho, J. M. V., Stirling, J. A. R., Venance, K. E., Ball, N. A., Moffatt, E., Chaves, M. L. S. C., Brandão, P. R. G., Romano, A. W. (2012) Carlosbarbosaite, ideally (UO2)2Nb2O6(OH)2·2H2O, a new hydrated uranyl niobate mineral with tunnels from Jaguaraçu, Minas Gerais, Brazil: description and crystal structure. Mineralogical Magazine, 76 (1) 75-90 doi:10.1180/minmag.2012.076.1.75
Lira, Raúl, Parra, Francisco J., Biglia, Marco E., Morello, Orquídea, Guereschi, Alina B. (2023) Genesis and New Mineral Chemistry Data of Carlosbarbosaite, a Potential U and Nb Ore Source from Miarolitic-, A-Type Granites and NYF Pegmatites of the La Chinchilla Pluton, Velasco Ranges, La Rioja, Argentina. The Canadian Journal of Mineralogy and Petrology, 61 (5) 927-964 doi:10.3749/2300008
Localities for Carlosbarbosaite
Showing 8 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.
Argentina | |
| Bardelli et al. (2018) |
Brazil (TL) | |
| Williams et al. (2011) +1 other reference |
Egypt | |
| Mahmoud et al. (2018) |
Italy | |
| Fernando Caboni et al. (2023) |
Madagascar | |
| Łukasz Kruszewski photo (ID: 1094393 ) |
Norway | |
| Husdal et al. (2021) |
| Husdal et al. (2021) | |
Poland | |
| Szopa et al. (2017) |
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Jaguaraçu pegmatite, Jaguaraçu, Minas Gerais, Brazil