Ashoverite
A valid IMA mineral species
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About Ashoverite
Formula:
Zn(OH)2
Colour:
Colourless, milky
Lustre:
Vitreous, Dull
Specific Gravity:
3.3
Crystal System:
Tetragonal
Name:
For the type locality.
This page provides mineralogical data about Ashoverite.
Unique Identifiers
Mindat ID:
453
Long-form identifier:
mindat:1:1:453:4
IMA Classification of Ashoverite
Approved
IMA Formula:
Zn2+(OH)2
Approval year:
1986
Classification of Ashoverite
4.FA.10
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
A : Hydroxides with OH, without H2O; corner-sharing tetrahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
A : Hydroxides with OH, without H2O; corner-sharing tetrahedra
6.2.11.1
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
7.5.3
7 : Oxides and Hydroxides
5 : Oxides of Zn, Cd and Hg
7 : Oxides and Hydroxides
5 : Oxides of Zn, Cd and Hg
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 |
|---|---|---|
| Aov | 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 Ashoverite
Vitreous, Dull
Transparency:
Translucent
Colour:
Colourless, milky
Streak:
White
Cleavage:
Perfect
on {001}
on {001}
Density:
3.3 g/cm3 (Measured) 3.44 g/cm3 (Calculated)
Optical Data of Ashoverite
Type:
Uniaxial (+)
RI values:
nω = 1.629 nε = 1.639
Max. Birefringence:
δ = 0.010
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:
Moderate
Chemistry of Ashoverite
Mindat Formula:
Zn(OH)2
Elements listed:
Crystallography of Ashoverite
Crystal System:
Tetragonal
Cell Parameters:
a = 6.825(2) Å, c = 33.36(4) Å
Ratio:
a:c = 1 : 4.888
Unit Cell V:
1,553.93 ų (Calculated from Unit Cell)
Z:
32
Comment:
Point Group: 4/m 2/m 2/m, 42m, or 4mm.; Space Group: I41/amd, I42d, or I41md.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.902 Å | (100) |
| 1.819 Å | (33) |
| 1.702 Å | (21) |
| 1.470 Å | (19) |
| 3.031 Å | (13) |
| 1.0063 Å | (13) |
| 3.332 Å | (11) |
Locality:
Reference:
Comments:
Recorded on type material
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 56 : Slag and smelter minerals (see also #51 and #55) |
Type Occurrence of Ashoverite
General Appearance of Type Material:
Square plates to about 0.5 mm, markedly thinning toward their edges; commonly in stellate groups of crystals intersecting at angles of 60°-70°
Place of Conservation of Type Material:
The Natural History Museum, London, England (No. 1982,5)
Geological Setting of Type Material:
Oxidized vein in limestone
Associated Minerals at Type Locality:
Synonyms of Ashoverite
Other Language Names for Ashoverite
Common Associates
Associations Based on Photo Data:
| 6 photos of Ashoverite associated with Fluorite | CaF2 |
| 5 photos of Ashoverite associated with Sweetite | Zn(OH)2 |
| 4 photos of Ashoverite associated with Calcite | CaCO3 |
| 3 photos of Ashoverite associated with Baryte | BaSO4 |
| 2 photos of Ashoverite associated with 'Unnamed (gamma-Zn(OH)2)' | γ-Zn(OH)2 |
| 1 photo of Ashoverite associated with Lepidocrocite | Fe3+O(OH) |
| 1 photo of Ashoverite associated with Hydrozincite | Zn5(CO3)2(OH)6 |
Related Minerals - Strunz-mindat Grouping
| 4.FA.05b | Clinobehoite | Be(OH)2 |
| 4.FA.05a | Behoite | Be(OH)2 |
| 4.FA.10 | Sweetite | Zn(OH)2 |
| 4.FA.10 | Wülfingite | Zn(OH)2 |
Fluorescence of Ashoverite
SW UV: bluish white
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 Ashoverite
mindat.org URL:
https://www.mindat.org/min-453.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 Ashoverite
Reference List:
Clark, A. M., Fejer, E. E., Cressey, G., Tandy, P. C. (1988) Ashoverite, a New Mineral, and Other Polymorphs of Zn(OH)2 from Milltown, Ashover, Derbyshire. Mineralogical Magazine, 52 (368) 699-702 doi:10.1180/minmag.1988.052.368.14
Localities for Ashoverite
Showing 8 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.
Germany | |
| Anthony (1997) |
| Schnorrer-Köhler (1988) | |
Italy | |
| Rivista Mineralogica Italiana (3) |
Namibia | |
| Walter Kahn specimen analyzed by SEM ... |
Romania | |
| HÎRTOPANU et al. (2025) |
Russia | |
| Ivashchenko et al. (2011, September) |
| Ivashchenko et al. (2011, September) | |
UK (TL) | |
| Clark et al. (1988) +2 other references |
Quick NavTopAbout AshoveriteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Milltown Quarry, Milltown, Ashover, North East Derbyshire District, Derbyshire, England, UK