Kroupaite
A valid IMA mineral species
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About Kroupaite
Formula:
KPb0.5[(UO2)8O4(OH)10] · 10H2O
Colour:
Orange-yellow
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
5.058 (Calculated)
Crystal System:
Orthorhombic
Name:
The new mineral is named after mining engineer Gustav Kroupa (born 30 August 1857 in Mutějovice near Rakovník, Bohemia, died 31 May 1935 in Vienna, Austria), mining engineer, in 1896 he became the head of the k.k. Uranfarbenfabrik in St. Joachimsthal (Jáchymov) until 1900. He approved and sent 10 tons of leachates after processing of uranium ore for uranium pigments to Marie-Curie Sklodowska and Pierre Curie, who were the first to discover and isolate 3 grams of RaCl2 from them.
Structurally related to leesite and metaschoepite.
Belongs to a group of minerals that may be important in uptaking radionuclides like 90Sr or 135Cs.
Belongs to a group of minerals that may be important in uptaking radionuclides like 90Sr or 135Cs.
Unique Identifiers
Mindat ID:
51971
Long-form identifier:
mindat:1:1:51971:7
GUID
(UUID V4):
(UUID V4):
1592bbe4-f784-43ba-8ef9-3deaf12253a4
IMA Classification of Kroupaite
Approved
IMA Formula:
KPb0.5[(UO2)8O4(OH)10] · 10H2O
Approval year:
2017
First published:
2020
Type description reference:
Plášil, Jakub, Kampf, Anthony R., Olds, Travis A., Sejkora, Jiří, Škoda, Radek, Burns, Peter C., Čejka, Jiří (2020) The new K, Pb-bearing uranyl-oxide mineral kroupaite: Crystal-chemical implications for the structures of uranyl-oxide hydroxy-hydrates. American Mineralogist, 105 (4) 561-568 doi:10.2138/am-2020-7311
Classification of Kroupaite
4.GB.85
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 |
---|---|---|
Kpa | 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 Kroupaite
Vitreous
Transparency:
Translucent
Colour:
Orange-yellow
Streak:
Light yellow
Hardness:
2 on Mohs scale
Hardness Data:
Measured
Comment:
Scratch tests
Tenacity:
Brittle
Cleavage:
Perfect
{100}
{100}
Fracture:
Irregular/Uneven
Density:
5.058 g/cm3 (Calculated)
Comment:
Not measured due to limited amount of materal. Calculated from empirical formula.
Optical Data of Kroupaite
Type:
Biaxial (-)
RI values:
nα = 1.691(2) nβ = 1.752(2) nγ = 1.768(2)
2V:
Measured: 53° (1), Calculated: 52.7°
Max Birefringence:
δ = 0.077
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
High
Pleochroism:
Visible
Comments:
X = colorless, Y = yellow, Z = yellow; X < Y ≈ Z
Comments:
X = a, Y = c, Z = b
Chemistry of Kroupaite
Mindat Formula:
KPb0.5[(UO2)8O4(OH)10] · 10H2O
Crystallography of Kroupaite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pbca
Setting:
Pbca
Cell Parameters:
a = 14.8201(8) Å, b = 14.0958(8) Å, c = 16.765(1) Å
Ratio:
a:b:c = 1.051 : 1 : 1.189
Unit Cell V:
3,502.23 ų (Calculated from Unit Cell)
Morphology:
Tablets flattened on {100}, with prominent forms {100}, {013} and {021}.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
7.407 Å | (100) |
3.602 Å | (59) |
3.224 Å | (78) |
2.572 Å | (16) |
2.035 Å | (21) |
1.978 Å | (11) |
1.798 Å | (10) |
1.747 Å | (7) |
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Near-surface Processes | |
27 : Radioactive decay; auto-oxidation | |
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] | |
47g : [Halogen-bearing surface weathering minerals] |
Type Occurrence of Kroupaite
General Appearance of Type Material:
Radial aggregates of thick platy, orange-yellow crystals, up to 1 mm, growing in interstices of gypsum crystals
Place of Conservation of Type Material:
Type material is deposited in the mineralogical collections of the National Museum in Prague, Czech Republic, catalogue number no. P1P 16/ 2017, and the Natural History Museum of Los Angeles County, Los Angeles, CA, USA, catalogue number 66572.
Associated Minerals at Type Locality:
Reference:
Plášil, J., Kampf, A.R., Olds, T.A., Sejkora, J., Škoda, R., Burns, P.C. and Čejka, J. (2020) The new K, Pb-bearing uranyl-oxide mineral kroupaite: Crystal-chemical implications for the structures of uranyl-oxide hydroxy-hydrates. American Mineralogist: 105: 561-568.
Synonyms of Kroupaite
Common Associates
Associated Minerals Based on Photo Data:
2 photos of Kroupaite associated with Jáchymovite | (UO2)8(SO4)(OH)14 · 13H2O |
1 photo of Kroupaite associated with Uranopilite | (UO2)6(SO4)O2(OH)6 · 14H2O |
1 photo of Kroupaite associated with Gypsum | CaSO4 · 2H2O |
1 photo of Kroupaite associated with Fourmarierite | Pb(UO2)4O3(OH)4 · 4H2O |
1 photo of Kroupaite associated with Compreignacite | K2(UO2)6O4(OH)6 · 7H2O |
1 photo of Kroupaite associated with Sklodowskite | Mg(UO2)2(SiO3OH)2 · 6H2O |
1 photo of Kroupaite associated with Uraninite | UO2 |
Related Minerals - Strunz-mindat Grouping
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.05 | Rameauite | K2Ca(UO2)6O6(OH)4 · 6H2O |
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 | Bauranoite | Ba(UO2)2(OH)6 · 1-2H2O |
4.GB.20 | Calciouranoite | (Ca,Ba,Pb)U2O7 · 5H2O |
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 | Metavandendriesscheite | PbU7O22 · nH2O n < 12 |
4.GB.40 | Vandendriesscheite | PbU7O22 · 12H2O |
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.75 | Carlosbarbosaite | (UO2)2Nb2O6(OH)2 · 2H2O |
4.GB.80 | Gauthierite | KPb[(UO2)7O5(OH)7] · 8H2O |
4.GB.90 | Leesite | K(H2O)2[(UO2)4O2(OH)5] · 3H2O |
4.GB.95 | Shinkolobweite | Pb1.25[U5+(H2O)2(U6+O2)5O8(OH)2](H2O)5 |
4.GB.95 | Nollmotzite | Mg[U5+(U6+O2)2O4F3] · 4H2O |
Fluorescence of Kroupaite
Not fluorescent
Other Information
Notes:
Soluble in dilute HCl, with no effervescence
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 Kroupaite
mindat.org URL:
https://www.mindat.org/min-51971.html
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Please feel free to link to this page.
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References for Kroupaite
Reference List:
Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2017) New minerals and nomenclature modifications approved in 2017, CNMNC Newsletter No 38. Mineralogical Magazine, 81 (4) 1033-1038 doi:10.1180/minmag.2017.081.062
Plášil, Jakub, Kampf, Anthony R., Olds, Travis A., Sejkora, Jiří, Škoda, Radek, Burns, Peter C., Čejka, Jiří (2020) The new K, Pb-bearing uranyl-oxide mineral kroupaite: Crystal-chemical implications for the structures of uranyl-oxide hydroxy-hydrates. American Mineralogist, 105 (4) 561-568 doi:10.2138/am-2020-7311
Localities for Kroupaite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Czech Republic | |
| Möhn et al. (12/2021) |
| Plášil et al. (2020) |
Desor (04/2022) | |
Germany | |
| Carsten Slotta sample |
| Gerstenberg et al. (11/21) +1 other reference |
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Jáchymov, Karlovy Vary District, Karlovy Vary Region, Czech Republic