Zýkaite
A valid IMA mineral species
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About Zýkaite
Václav Zýka
Formula:
Fe3+4(AsO4)3(SO4)(OH) · 15H2O
Colour:
Greyish white, light yellow, light green
Lustre:
Dull
Hardness:
2
Specific Gravity:
2.50
Crystal System:
Orthorhombic
Member of:
Name:
Named after Dr. Václav Zýka (1926 – 1990), Czech geologist, geochemist, and Director of the Institute of Raw Materials, Kutná Hora, Czech Republic.
Name Encoding
ASCII-7:
Zykaite
Unique Identifiers
Mindat ID:
4437
Long-form identifier:
mindat:1:1:4437:6
IMA Classification of Zýkaite
Approved
IMA Formula:
Fe3+4(As5+O4)3S6+O4(OH)·15H2O
Approval year:
1976
First published:
1978
Classification of Zýkaite
8.DB.45
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
B : With only medium-sized cations, (OH, etc.):RO4< 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
B : With only medium-sized cations, (OH, etc.):RO4< 1:1
43.5.3.2
43 : COMPOUND PHOSPHATES, ETC.
5 : Hydrated Compound Phosphates, etc·, Containing Hydroxyl or Halogen
43 : COMPOUND PHOSPHATES, ETC.
5 : Hydrated Compound Phosphates, etc·, Containing Hydroxyl or Halogen
22.3.28
22 : Phosphates, Arsenates or Vanadates with other Anions
3 : Phosphates, arsenates or vanadates with sulphates
22 : Phosphates, Arsenates or Vanadates with other Anions
3 : Phosphates, arsenates or vanadates with sulphates
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 |
|---|---|---|
| Zýk | 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 Zýkaite
Dull
Colour:
Greyish white, light yellow, light green
Streak:
Pale yellowish
Hardness:
2 on Mohs scale
Tenacity:
Waxy
Fracture:
Irregular/Uneven
Density:
2.50 g/cm3 (Measured) 2.504 g/cm3 (Calculated)
Optical Data of Zýkaite
Type:
Biaxial (-)
RI values:
nα = 1.632 nβ = 1.635 - 1.636 nγ = 1.646
2V:
Measured: 60° , Calculated: 56° to 66°
Max. Birefringence:
δ = 0.014
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:
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:
weak to distinct
Chemistry of Zýkaite
Mindat Formula:
Fe3+4(AsO4)3(SO4)(OH) · 15H2O
Element Weights:
Crystallography of Zýkaite
Crystal System:
Orthorhombic
Class (H-M):
222 - Disphenoidal
Space Group:
P222
Cell Parameters:
a = 20.853(20) Å, b = 7.033(4) Å, c = 36.991(23) Å
Ratio:
a:b:c = 2.965 : 1 : 5.26
Unit Cell V:
5,425.07 ų (Calculated from Unit Cell)
Z:
8
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 10.6 Å | (7) |
| 10.4 Å | (10) |
| 6.92 Å | (4) |
| 5.610 Å | (4) |
| 3.812 Å | (4) |
| 3.516 Å | (3) |
| 2.831 Å | (4) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47b : [Sulfates and sulfites] | |
| 47d : [Arsenates, antimonates, selenates, bismuthinates] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Type Occurrence of Zýkaite
Place of Conservation of Type Material:
Charles University, Prague, Czech Republic, 20558.
National School of Mines, Paris, France.
National Museum of Natural History, Washington, D.C., USA, 144940, 144941.
National School of Mines, Paris, France.
National Museum of Natural History, Washington, D.C., USA, 144940, 144941.
Geological Setting of Type Material:
alteration product of arsenopyrite and pyrite
Associated Minerals at Type Locality:
Synonyms of Zýkaite
Other Language Names for Zýkaite
Relationship of Zýkaite to other Species
Member of:
Other Members of Sanjuanite-Destinezite Group:
| Destinezite | Fe3+2(PO4)(SO4)(OH) · 6H2O | Tric. 1 : P1 |
| Sanjuanite | Al2(PO4)(SO4)(OH) · 9H2O | Tric. |
| Sarmientite | Fe3+2(AsO4)(SO4)(OH) · 5H2O | Mon. 2/m : P21/b |
Common Associates
Associations Based on Photo Data:
| 6 photos of Zýkaite associated with Kaňkite | FeAsO4 · 3.5H2O |
| 2 photos of Zýkaite associated with Bukovskýite | Fe3+2(AsO4)(SO4)(OH) · 9H2O |
| 1 photo of Zýkaite associated with Arsenopyrite | FeAsS |
Related Minerals - Strunz-mindat Grouping
| 8.DB. | Arangasite | Al2F(PO4)(SO4) · 9H2O |
| 8.DB. | Höslite | Fe3+3(VO4)2(SO4)(OH)(H2O)4 · 3H2O |
| 8.DB. | Camaronesite | [Fe3+(H2O)2(PO3OH)]2(SO4) · 1-2H2O |
| 8.DB.05 | Destinezite | Fe3+2(PO4)(SO4)(OH) · 6H2O |
| 8.DB.05 | Pitticite | (Fe, AsO4, H2O) (?) |
| 8.DB.05 | Diadochite | Fe3+2(PO4)(SO4)(OH) · 6H2O |
| 8.DB.07 | Wilhelmgümbelite | ZnFe2+Fe3+3(PO4)3(OH)4(H2O)5 · 2H2O |
| 8.DB.07 | Schmidite | [Zn2(Fe3+,Mn2+)2Fe3+(PO4)3(OH)3(H2O)6] · 2H2O |
| 8.DB.07 | Wildenauerite | Zn(Fe3+,Mn2+)2MnFe3+(PO4)3(OH)3(H2O)6 · 2H2O |
| 8.DB.10 | Vashegyite | Al11(PO4)9(OH)6 · 38H2O |
| 8.DB.15 | Schoonerite | ZnMn2+Fe2+2Fe3+(PO4)3(OH)2 · 9H2O |
| 8.DB.20 | Sinkankasite | Mn2+Al(PO3OH)2(OH) · 6H2O |
| 8.DB.25 | Mitryaevaite | Al6(PO4)((P,S)O3(OH,O))2F2(OH)2 · 14.5H2O |
| 8.DB.30 | Sanjuanite | Al2(PO4)(SO4)(OH) · 9H2O |
| 8.DB.35 | Sarmientite | Fe3+2(AsO4)(SO4)(OH) · 5H2O |
| 8.DB.40 | Bukovskýite | Fe3+2(AsO4)(SO4)(OH) · 9H2O |
| 8.DB.40 | Manganflurlite | ZnMn2+3Fe3+(PO4)3(OH)2(H2O)7 · 2H2O |
| 8.DB.40 | Flurlite | Zn3Mn2+Fe3+(PO4)3(OH)2 · 9H2O |
| 8.DB.42 | Bohuslavite | Fe3+4(PO4)3(SO4)(OH) · nH2O |
| 8.DB.47 | Lapeyreite | Cu3O[AsO3(OH)]2 · 0.75H2O |
| 8.DB.50 | Rossiantonite | Al3(PO4)(SO4)2(OH)2(H2O)14 |
| 8.DB.50 | Giniite | Fe2+Fe3+4(PO4)3(OH)5 · 2H2O |
| 8.DB.52 | 'Arctowskite' | Al9(PO4)8(OH)3 · 27H2O |
| 8.DB.55 | Sasaite | (Al,Fe3+)14(PO4)11(SO4)(OH)7 · 83H2O |
| 8.DB.60 | Mcauslanite | Fe3Al2(PO4)3(PO3OH)F · 18H2O |
| 8.DB.65 | Goldquarryite | CuCd2Al3(PO4)4F2(H2O,F)2 · 10H2O |
| 8.DB.70 | Birchite | Cd2Cu2(PO4)2(SO4) · 5H2O |
| 8.DB.75 | Braithwaiteite | NaCu5(Ti4+Sb5+)(AsO4)4(HAsO4)2O2 · 8H2O |
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 Zýkaite
mindat.org URL:
https://www.mindat.org/min-4437.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 Zýkaite
Reference List:
Localities for Zýkaite
Showing 14 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.
Austria | |
| Auer (2023) |
Czech Republic | |
| www.mindat.org (2022) |
| Čech et al. (1978) |
| Hloušek et al. (2002) |
Germany | |
| www.mineralienatlas.de (n.d.) |
| Witzke et al. (1993) |
| Witzke (2023) |
| 90. +1 other reference |
| Witzke et al. (1993) |
Greece | |
| Rieck et al. (2018) |
New Zealand | |
| Haffert et al. (2010) |
Poland | |
| Siuda (2004) |
Russia | |
| Ivashchenko et al. (2018, June) |
Switzerland | |
| Ansermet S.; Meisser N. (2026) |
Quick NavTopAbout ZýkaiteName EncodingUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Wilhelm Mine, Stara Góra deposit, Radzimowice, Gmina Bolków, Jawor County, Lower Silesian Voivodeship, Poland