Tvrdýite
A valid IMA mineral species
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About Tvrdýite
Jaromír Tvrdý
Formula:
Fe2+Fe3+2Al3(PO4)4(OH)5(H2O)4 · 2H2O
Colour:
Silvery to olive-greyish-green
Lustre:
Pearly
Hardness:
3 - 4
Specific Gravity:
2.834 (Calculated)
Crystal System:
Monoclinic
Member of:
Name:
Named in honor of Jaromír Tvrdý (b. 1959) from Liberec, Czech Republic, for his contributions to mineralogy and economic geology. The pronunciation is /twe:(r)’di:ait/, or similar to ‘twerdeeite’.
Type Locality:
Isostructural with:
Isostructural with beraunite. Chemically similar to cacoxenite, childrenite, ferrivauxite, metavauxite, paravauxite, sigloite, and vauxite; also matulaite.
The type material is significantly enriched in Zn.
Difference from beraunite: Al dominance in 2/4 M sites.
The type material is significantly enriched in Zn.
Difference from beraunite: Al dominance in 2/4 M sites.
Name Encoding
ASCII-7:
Tvrdyite
Unique Identifiers
Mindat ID:
46532
Long-form identifier:
mindat:1:1:46532:8
IMA Classification of Tvrdýite
Approved
IMA Formula:
Fe2+Fe3+2Al3(PO4)4(OH)5(H2O)4·2H2O
Approval year:
2014
First published:
2016
Classification of Tvrdýite
8.DC.27
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
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 for Standard |
|---|---|---|
| Tvr | 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 Tvrdýite
Pearly
Colour:
Silvery to olive-greyish-green
Streak:
Greyish-white
Hardness:
3 - 4 on Mohs scale
Comment:
ca. 3-4
Tenacity:
Very brittle
Cleavage:
Distinct/Good
{100}
{100}
Comment:
Fibres are somewhat flexible.
Density:
2.834 g/cm3 (Calculated)
Optical Data of Tvrdýite
Type:
Biaxial (-)
RI values:
nα = 1.650(2) nβ = 1.671(1) nγ = 1.677(1)
2V:
Measured: 56° (1)
Max. Birefringence:
δ = 0.027
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.
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.
Surface Relief:
Moderate
Dispersion:
strong (r > v)
Pleochroism:
Strong
Comments:
X = greenish-blue; Y = Z = yellowish-orange.
Comments:
Absorption: X >> Y > Z .
Chemistry of Tvrdýite
Mindat Formula:
Fe2+Fe3+2Al3(PO4)4(OH)5(H2O)4 · 2H2O
Element Weights:
Common Impurities:
Zn,As,F
Crystallography of Tvrdýite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/b
Setting:
C2/c
Cell Parameters:
a = 20.564(4) Å, b = 5.101(1) Å, c = 18.883(4) Å
β = 93.68(3)°
β = 93.68(3)°
Ratio:
a:b:c = 4.031 : 1 : 3.702
Unit Cell V:
1976.7 ų
Z:
4
Morphology:
Acicular to fibrous crystals 0.5 - 5 μm in diameter and up to 300 μm long; may be in radiating aggregates, up to 3 mm.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 10.227 Å | (100) |
| 9.400 Å | (6) |
| 7.156 Å | (14) |
| 5.120 Å | (7) |
| 3.416 Å | (11) |
| 3.278 Å | (6) |
| 2.562 Å | (5) |
| 2.051 Å | (3) |
Locality:
Reference:
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] |
Type Occurrence of Tvrdýite
General Appearance of Type Material:
Acicular to fibrous; radiating aggregates.
Place of Conservation of Type Material:
Type material is housed in the collections of the Department of Mineralogy and Petrology, National Museum Prague, Cirkusova´ 1740, CZ- 193 00 Prague 9, Czech Republic, catalogue number P1P 11/2014.
Geological Setting of Type Material:
Cavity in quartz gangue.
Associated Minerals at Type Locality:
Synonyms of Tvrdýite
Other Language Names for Tvrdýite
Relationship of Tvrdýite to other Species
Member of:
Other Members of Beraunite Group:
| Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O | Mon. m : Bb |
| Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O | Mon. 2/m : B2/b |
| Zincoberaunite | ZnFe3+5(PO4)4(OH)5 · 6H2O | Mon. 2/m : B2/b |
Common Associates
Related Minerals - Strunz-mindat Grouping
| 8.DC. | Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O |
| 8.DC. | Césarferreiraite | Fe2+ Fe3+2(AsO4)2(OH)2 · 8H2O |
| 8.DC. | Ferrivauxite | Fe3+Al2(PO4)2(OH)3 · 5H2O |
| 8.DC. | Ianbruceite | Zn2(AsO4)(OH) · 3H2O |
| 8.DC.05 | Nissonite | Cu2Mg2(PO4)2(OH)2 · 5H2O |
| 8.DC.07 | Euchroite | Cu2(AsO4)(OH) · 3H2O |
| 8.DC.10 | Legrandite | Zn2(AsO4)(OH) · H2O |
| 8.DC.12 | Strashimirite | Cu8(AsO4)4(OH)4 · 5H2O |
| 8.DC.15 | Earlshannonite | Mn2+Fe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Kunatite | CuFe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | 'UM2006-27-PO:FeHZn' | ZnFe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | 'UKI-2006-(PO:AlCuFeH)' | Fe2+Al3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Cobaltarthurite | CoFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Arthurite | CuFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Ojuelaite | ZnFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Whitmoreite | Fe2+Fe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Bendadaite | Fe2+Fe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.17 | Kleemanite | ZnAl2(PO4)2(OH)2 · 3H2O |
| 8.DC.20 | Magnesiobermanite | MgMn3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.20 | Bermanite | Mn2+Mn3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.20 | Coralloite | Mn2+Mn3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.22 | Kovdorskite | Mg2(PO4)(OH) · 3H2O |
| 8.DC.25 | Zincostrunzite | ZnFe3+2(PO4)2(OH)2 · 6.5H2O |
| 8.DC.25 | Metavauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.25 | Metavivianite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.25 | Ferristrunzite | Fe3+Fe3+2(PO4)2(OH)3 · 5H2O |
| 8.DC.25 | Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.25 | Ferrostrunzite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.27 | Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O |
| 8.DC.27 | Zincoberaunite | ZnFe3+5(PO4)4(OH)5 · 6H2O |
| 8.DC.30 | Maghrebite | MgAl2(AsO4)2(OH)2 · 8H2O |
| 8.DC.30 | Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Sigloite | Fe3+Al2(PO4)2(OH)3 · 7H2O |
| 8.DC.30 | Nordgauite | MnAl2(PO4)2(F,OH)2 · 5H2O |
| 8.DC.30 | Kayrobertsonite | [MnAl2(PO4)2(OH)2(H2O)4] · 2H2O |
| 8.DC.30 | Kummerite | Mn2+Fe3+Al(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Stewartite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Gordonite | MgAl2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Pseudolaueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.32 | Kamarizaite | Fe3+3(AsO4)2(OH)3 · 3H2O |
| 8.DC.32 | Tinticite | Fe3+3(PO4)2(OH)3 · 3H2O |
| 8.DC.35 | Vauxite | Fe2+Al2(PO4)2(OH)2 · 6H2O |
| 8.DC.37 | Vantasselite | Al4(PO4)3(OH)3 · 9H2O |
| 8.DC.40 | Cacoxenite | Fe3+24AlO6(PO4)17(OH)12 · 75H2O |
| 8.DC.45 | Souzalite | Mg3Al4(PO4)4(OH)6 · 2H2O |
| 8.DC.45 | Gormanite | (Fe2+,Mg)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O |
| 8.DC.47 | Kingite | Al3(PO4)2F2(OH) · 7H2O |
| 8.DC.50 | Allanpringite | Fe3+3(PO4)2(OH)3 · 5H2O |
| 8.DC.50 | Fluorwavellite | Al3(PO4)2(OH)2F · 5H2O |
| 8.DC.50 | Wavellite | Al3(PO4)2(OH)3 · 5H2O |
| 8.DC.52 | Kribergite | Al5(PO4)3(SO4)(OH)4 · 4H2O |
| 8.DC.55 | Mapimite | Zn2Fe3+3(AsO4)3(OH)4 · 10H2O |
| 8.DC.57 | Ogdensburgite | Ca2Fe3+4(Zn,Mn2+)(AsO4)4(OH)6 · 6H2O |
| 8.DC.60 | Cloncurryite | Cu0.5(VO)0.5Al2(PO4)2F2 · 5H2O |
| 8.DC.60 | Nevadaite | (Cu2+,Al,V3+)6Al8(PO4)8F8(OH)2 · 22H2O |
| 8.DC.62 | Kenngottite | Mn2+3Fe3+4(PO4)4(OH)6(H2O)2 |
| 8.DC.67 | Molinelloite | Cu(H2O)(OH)V4+O(V5+O4) |
| 8.DC.70 | Whitecapsite | H16Fe2+5Fe3+14Sb3+6(AsO4)18O16 · 120H2O |
| 8.DC.75 | Heimite | PbCu2(AsO4)(OH)3 · 2H2O |
| 8.DC.80 | Lednevite | Cu[PO3(OH)] · H2O |
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 Tvrdýite
mindat.org URL:
https://www.mindat.org/min-46532.html
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References for Tvrdýite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2015) New minerals and nomenclature modifications approved in 2014 and 2015. Newsletter No 23. Mineralogical Magazine, 79 (1) 51-58 doi:10.1180/minmag.2015.079.1.05
Sejkora, J., Grey, I. E., Kampf, A. R., Price, J. R., Čejka, J. (2016) Tvrdýite, Fe2+Fe32+Al3(PO4)4(OH)5(OH2)4·2H2O, a new phosphate mineral from Krásno near Horní Slavkov, Czech Republic. Mineralogical Magazine, 80 (6) 1077-1088 doi:10.1180/minmag.2016.080.045
Localities for Tvrdýite
Showing 3 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.
Czech Republic | |
| www.researchgate.net (n.d.) +2 other references |
| Williams et al. (2015) +1 other reference |
Germany | |
| 92. (p. 44) +2 other references |
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Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany