Kamitugaite
A valid IMA mineral species
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About Kamitugaite
Kamituga
Formula:
PbAl[(UO2)5(PO4)2.38(AsO4)0.62O2(OH)2] · 11.5H2O
Formula inferred from the crystal structure refinement (Plášil 2017).
Colour:
Yellow
Lustre:
Vitreous
Hardness:
3
Specific Gravity:
4.03
Crystal System:
Triclinic
Name:
Named in 1984 by M. Deliens and P. Piret for Kamituga, the mining center of Kivu, near the type locality.
Type Locality:
This page provides mineralogical data about Kamitugaite.
Unique Identifiers
Mindat ID:
2148
Long-form identifier:
mindat:1:1:2148:3
IMA Classification of Kamitugaite
Approved
IMA Formula:
Pb2+Al(U6+O2)5(PO4)3O2(OH)2(H2O)11.5
Approval year:
1983
First published:
1984
Classification of Kamitugaite
8.ED.15
8 : PHOSPHATES, ARSENATES, VANADATES
E : Uranyl phosphates and arsenates
D : Unclassified
8 : PHOSPHATES, ARSENATES, VANADATES
E : Uranyl phosphates and arsenates
D : Unclassified
42.13.11.1
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
13 : Miscellaneous
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
13 : Miscellaneous
19.10.3
19 : Phosphates
10 : Phosphates of Pb, Th, V and Bi
19 : Phosphates
10 : Phosphates of Pb, Th, V and Bi
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 |
|---|---|---|
| Ktg | 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 Kamitugaite
Vitreous
Transparency:
Transparent
Colour:
Yellow
Streak:
White
Hardness:
3 on Mohs scale
Hardness Data:
Estimated
Density:
4.03 g/cm3 (Measured) 4.47 g/cm3 (Calculated)
Optical Data of Kamitugaite
Type:
Biaxial (-)
RI values:
nα = 1.709 nβ = 1.735 nγ = 1.744
2V:
Measured: 60° , Calculated: 60°
Max. Birefringence:
δ = 0.035
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 weak
Pleochroism:
Visible
Comments:
X = colorless, Y = yellow
Comments:
X ≃ b∗; Y ∧ a = 1◦–2◦; Z ⊥ a and b∗.
Chemistry of Kamitugaite
Mindat Formula:
PbAl[(UO2)5(PO4)2.38(AsO4)0.62O2(OH)2] · 11.5H2O
Formula inferred from the crystal structure refinement (Plášil 2017).
Formula inferred from the crystal structure refinement (Plášil 2017).
Element Weights:
Crystallography of Kamitugaite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Setting:
P1
Cell Parameters:
a = 9.0296(8) Å, b = 10.9557(8) Å, c = 15.8249(15) Å
α = 89.585(7)°, β = 85.349(8)°, γ = 84.251(7)°
α = 89.585(7)°, β = 85.349(8)°, γ = 84.251(7)°
Ratio:
a:b:c = 0.824 : 1 : 1.444
Unit Cell V:
1,552.48 ų (Calculated from Unit Cell)
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.95 Å | (100) |
| 3.972 Å | (80) |
| 3.271 Å | (40) |
| 3.175 Å | (40) |
| 15.92 Å | (30) |
| 3.493 Å | (30) |
| 4.307 Å | (25) |
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] | |
| 47d : [Arsenates, antimonates, selenates, bismuthinates] | |
| 47f : [Uranyl (U⁶⁺) minerals] |
Type Occurrence of Kamitugaite
General Appearance of Type Material:
Thin plates with a maximum length of 0.5 mm.
Place of Conservation of Type Material:
Royal Museum of Central Africa, Tervuren, Belgium, RMG13985, RMG13986
Geological Setting of Type Material:
Quartz-albite-muscovite pegmatite.
Associated Minerals at Type Locality:
Synonyms of Kamitugaite
Other Language Names for Kamitugaite
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 8.ED.05 | Moreauite | Al3(UO2)(PO4)3(OH)2 · 13H2O |
| 8.ED.10 | Šreinite | Pb(BiO)3(UO2)4(PO4)2(OH)7 · 4H2O |
| 8.ED.10 | Metalodèvite | Zn(UO2)2(AsO4)2 · 10H2O |
| 8.ED.10 | Asselbornite | Pb(BiO)3(UO2)4(AsO4)2(OH)7 · 4H2O |
| 8.ED.20 | Nielsbohrite | K(UO2)3(AsO4)(OH)4 · H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 54.8537% | 13,713,425 | 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
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 Kamitugaite
mindat.org URL:
https://www.mindat.org/min-2148.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 Kamitugaite
Reference List:
Deliens, Michel; Piret, Paul (1984) La kamitugaïte, PbAl(UO2)5[(P,As)O4]2(OH)9.9,5 H2O, nouveau minéral de Kobokobo, Kivu, Zaïre. Bulletin de la Société française de Minéralogie et de Cristallographie, 107 (1). 15-19 doi:10.3406/bulmi.1984.7788
Localities for Kamitugaite
Showing 2 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. (1984) |
USA | |
| pers. comm. Josef Vajdak to C. Lemanski (2002) +1 other reference |
Quick NavTopAbout KamitugaiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
Kobokobo pegmatite, Mwenga Territory, South Kivu, DR Congo