Horákite
A valid IMA mineral species
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About Horákite
Formula:
(Bi7O7OH)[(UO2)4(PO4)2(AsO4)2(OH)2] · 3.5H2O
Colour:
Greenish-yellow to pale yellow
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
6.358 (Calculated)
Crystal System:
Monoclinic
Name:
Horákite is named after Ing. František Horák (1882–1919) served from 1916 to 1918 as bergadjunkt and the responsible head of the Radium factory in St. Joachimsthal (Jáchymov) and his grandson MUDr. (M.D.) Vladimír Horák (born 1964) is an amateur mineral collector and historian, focused on the history of mining in Jáchymov.
New structure type. Quite unique with phosphate and arsenate groups occurring separately.
Formed by supergene alteration.
Formed by supergene alteration.
Unique Identifiers
Mindat ID:
51973
Long-form identifier:
mindat:1:1:51973:5
GUID
(UUID V4):
(UUID V4):
ebcb425b-39b7-41b0-b246-3abe8d2aa60b
IMA Classification of Horákite
Approved
Approval year:
2017
First published:
2018
Classification of Horákite
8.EB.60
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
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 |
---|---|---|
Hor | 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 Horákite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Greenish-yellow to pale yellow
Streak:
Light yellow
Hardness:
2 on Mohs scale
Hardness Data:
Estimated
Cleavage:
Perfect
on {100}
on {100}
Density:
6.358 g/cm3 (Calculated)
Optical Data of Horákite
Type:
Biaxial (+)
RI values:
nα = 1.810 nβ = 1.810 nγ = 1.880
2V:
Measured: 78° , Calculated: 83°
Max Birefringence:
δ = 0.070
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:
Very High
Pleochroism:
Non-pleochroic
Comments:
Optical orientation is X = b, Z ≈ c
Chemistry of Horákite
Mindat Formula:
(Bi7O7OH)[(UO2)4(PO4)2(AsO4)2(OH)2] · 3.5H2O
Crystallography of Horákite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 21.374(2) Å, b = 15.451(3) Å, c = 12.168(2) Å
β = 122.26(1)°
β = 122.26(1)°
Ratio:
a:b:c = 1.383 : 1 : 0.788
Unit Cell V:
3398.1 ų
Z:
4
Morphology:
Prismatic crystals; clusters of acicular aggregates
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
11.77 Å | (100) |
6.21 Å | (23) |
5.55 Å | (23) |
4.185 Å | (27) |
3.543 Å | (61) |
3.287 Å | (20) |
3.144 Å | (58) |
3.017 Å | (98) |
Comments:
From Type Description.
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 Horákite
General Appearance of Type Material:
Greenish-yellow to pale yellow prismatic crystals clustering to acicular aggregates, up to 1 mm across.
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 17/2017, and the Natural History Museum of Los Angeles County, Los Angeles, CA, USA, catalogue number 66575
Empirical Formula of Type Material:
(Bi7.01Pb0.14)O7OH[(U1.01O2)4(P1.03O4)2(As0.74Si0.23O4)2(OH)2]·3.5H2O
Associated Minerals at Type Locality:
Reference:
Plášil, J., Kampf, A.R., Sejkora, J., Čejka, J., Škoda, R., Tvrdý, J. (2018): Horákite, a new hydrated bismuth uranyl-arsenate-phosphate mineral from Jáchymov (Czech Republic) with a unique uranyl-anion topology. Journal of Geosciences, 63: 265-276.
Synonyms of Horákite
Related Minerals - Strunz-mindat Grouping
8.EB. | Meta-autunite Group | A1-2(UO2)2(TO4)2 · 5-10H2O |
8.EB.05 | Autunite | Ca(UO2)2(PO4)2 · 10-12H2O |
8.EB.05 | Heinrichite | Ba(UO2)2(AsO4)2 · 10H2O |
8.EB.05 | Kahlerite | Fe(UO2)2(AsO4)2 · 12H2O |
8.EB.05 | Hydronováčekite | Mg(UO2)2(AsO4)2 · 12H2O |
8.EB.05 | Saléeite | Mg(UO2)2(PO4)2 · 10H2O |
8.EB.05 | Torbernite | Cu(UO2)2(PO4)2 · 12H2O |
8.EB.05 | Uranocircite | Ba(UO2)2(PO4)2 · 10H2O |
8.EB.05 | Uranospinite | Ca(UO2)2(AsO4)2 · 10H2O |
8.EB.05 | Xiangjiangite | (Fe3+,Al)(UO2)4(PO4)2(SO4)2(OH) · 22H2O |
8.EB.05 | Zeunerite | Cu(UO2)2(AsO4)2 · 12H2O |
8.EB.05 | Metarauchite | Ni(UO2)2(AsO4)2 · 8H2O |
8.EB.05 | Nováčekite | Mg(UO2)2(AsO4)2 · 10H2O |
8.EB.05 | Rauchite | Ni(UO2)2(AsO4)2 · 10H2O |
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 | 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.10 | Metanatroautunite | Na(UO2)(PO4)(H2O)3 |
8.EB.15 | Abernathyite | K(UO2)(AsO4) · 3H2O |
8.EB.15 | Chernikovite | (H3O)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 | Uramphite | (NH4)2(UO2)2(PO4)2 · 6H2O |
8.EB.15 | Uramarsite | (NH4)(UO2)(AsO4) · 3H2O |
8.EB.20 | Threadgoldite | Al(UO2)2(PO4)2(OH) · 8H2O |
8.EB.20 | Chistyakovaite | Al(UO2)2(AsO4)2(F,OH) · 6.5H2O |
8.EB.25 | Arsenuranospathite | Al(UO2)2(AsO4)2F · 20H2O |
8.EB.25 | Uranospathite | (Al,◻)(UO2)2(PO4)2F · 20(H2O,F) |
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 | Sabugalite | HAl(UO2)4(PO4)4 · 16H2O |
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 Horákite
mindat.org URL:
https://www.mindat.org/min-51973.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Horákite
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
Localities for Horákite
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 (TL) | |
| Hålenius et al. (2017) +2 other references |
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Jáchymov, Karlovy Vary District, Karlovy Vary Region, Czech Republic