Ammonioalunite
A valid IMA mineral species
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About Ammonioalunite
Formula:
(NH4)Al3(SO4)2(OH)6
Colour:
Grayish white
Lustre:
Vitreous
Hardness:
2 - 3
Specific Gravity:
2.4
Crystal System:
Trigonal
Member of:
Name:
The name is derived from "alunite" since it is a member of the Alunite Sub-group. The "Ammonio" prefix designates that it is the (NH4)-dominant member of the sub-group.
This page provides mineralogical data about Ammonioalunite.
Unique Identifiers
Mindat ID:
203
Long-form identifier:
mindat:1:1:203:1
IMA Classification of Ammonioalunite
Approved
IMA Formula:
N3-H4Al3(S6+O4)2(OH)6
Approval year:
1986
Classification of Ammonioalunite
7.BC.10
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
B : Sulfates (selenates, etc.) with additional anions, without H2O
C : With medium-sized and large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
B : Sulfates (selenates, etc.) with additional anions, without H2O
C : With medium-sized and large cations
30.2.4.6
30 : ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN
2 : (AB)2(XO4)Zq
30 : ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN
2 : (AB)2(XO4)Zq
25.1.10
25 : Sulphates
1 : Sulphates of the alkali metals and ammonium
25 : Sulphates
1 : Sulphates of the alkali metals and ammonium
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 |
|---|---|---|
| Aalu | 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 Ammonioalunite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Grayish white
Comment:
colorless in thin section.
Streak:
White
Hardness:
2 - 3 on Mohs scale
Cleavage:
Perfect
perfect on {0001}(by analogy with the alunite group).
perfect on {0001}(by analogy with the alunite group).
Density:
2.4 g/cm3 (Measured) 2.58 g/cm3 (Calculated)
Optical Data of Ammonioalunite
Type:
Uniaxial (+)
RI values:
nω = 1.590(5) nε = 1.602(5)
Max. Birefringence:
δ = 0.012
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 (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 uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Chemistry of Ammonioalunite
Mindat Formula:
(NH4)Al3(SO4)2(OH)6
Element Weights:
Crystallography of Ammonioalunite
Crystal System:
Trigonal
Cell Parameters:
a = 7.01 Å, c = 17.88 Å
Ratio:
a:c = 1 : 2.551
Unit Cell V:
760.91 ų (Calculated from Unit Cell)
Z:
3
Morphology:
As rhombohedral crystals, to 20 μm, forming granular masses.
Comment:
Point Group: 3 2/m or 3m; Space Group: R3m or R3m. a
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.023 Å | (100) |
| 5.04 Å | (93) |
| 2.996 Å | (50) |
| 1.917 Å | (32) |
| 2.353 Å | (31) |
| 1.753 Å | (21) |
| 3.514 Å | (19) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 14 : Hot springs, geysers, and other subaerial geothermal minerals | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 49 : Oxic cellular biomineralization (see also #44) | <0.54 |
| 50 : Coal and/or oil shale minerals | <0.36 |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 54 : Coal and other mine fire minerals (see also #51 and #56) |
Type Occurrence of Ammonioalunite
General Appearance of Type Material:
As rhombohedral crystals, to 20 µm, forming granular masses.
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, 145596.
Geological Setting of Type Material:
Formed in hot springs under very acid conditions, rich in ammonium and sulfate, poor in potassium, below 100 C.
Associated Minerals at Type Locality:
Synonyms of Ammonioalunite
Other Language Names for Ammonioalunite
Dutch:Ammonioaluniet
French:Ammonioalunite
German:Ammonioalunit
Norwegian:Ammonioalunitt
Spanish:Ammonioalunita
Relationship of Ammonioalunite to other Species
Member of:
Other Members of Alunite Group:
| Alunite | KAl3(SO4)2(OH)6 | Trig. 3m : R3m |
| Ammoniojarosite | (NH4)Fe3+3(SO4)2(OH)6 | Trig. 3m : R3m |
| Argentojarosite | AgFe3+3(SO4)2(OH)6 | Trig. 3m : R3m |
| Beaverite-(Cu) | Pb(Fe3+2Cu)(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Beaverite-(Zn) | Pb(Fe3+2Zn)(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Dorallcharite | TlFe3+3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Huangite | Ca0.5Al3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Hydroniumjarosite | (H3O)Fe3+3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Jarosite | KFe3+3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Natroalunite | NaAl3(SO4)2(OH)6 | Trig. 3m : R3m |
| 'Natroalunite-2c' | (Na,Ca0.5,K)Al3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Natrojarosite | NaFe3(SO4)2(OH)6 | Trig. 3m : R3m |
| Osarizawaite | Pb(Al2Cu2+)(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Plumbojarosite | Pb0.5Fe3+3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Schlossmacherite | (H3O)Al3(SO4)2(OH)6 | Trig. 3m(32/m) : R3m |
| Walthierite | Ba0.5Al3(SO4)2(OH)6 | Trig. |
Common Associates
Associations Based on Photo Data:
| 2 photos of Ammonioalunite associated with Ammoniojarosite | (NH4)Fe3+3(SO4)2(OH)6 |
| 1 photo of Ammonioalunite associated with Godovikovite | (NH4)Al(SO4)2 |
| 1 photo of Ammonioalunite associated with Pyracmonite | (NH4)3Fe(SO4)3 |
| 1 photo of Ammonioalunite associated with Kremersite | (NH4,K)2[Fe3+Cl5(H2O)] |
| 1 photo of Ammonioalunite associated with Tschermigite | (NH4)Al(SO4)2 · 12H2O |
Related Minerals - Strunz-mindat Grouping
| 7.BC. | Viskontite | Pb5Cu2(SO4)3(SeO3)(OH)6 |
| 7.BC. | Zincochenite | Pb4Zn(SO4)2(OH)6 |
| 7.BC. | D'Ansite-(Mn) | Na21Mn2+(SO4)10Cl3 |
| 7.BC. | D'Ansite-(Fe) | Na21Fe2+(SO4)10Cl3 |
| 7.BC. | Acmonidesite | (NH4,K,Pb)8NaFe2+4(SO4)5Cl8 |
| 7.BC. | Adranosite | (NH4)4NaAl2(SO4)4Cl(OH)2 |
| 7.BC. | Chromviskontite | Pb5Cu2(CrO4)3(SeO3)(OH)6 |
| 7.BC. | Backite | Pb2AlTeO6Cl |
| 7.BC. | Adranosite-(Fe) | (NH4)4NaFe3+2(SO4)4Cl(OH)2 |
| 7.BC. | Agaite | Pb3CuTeO5(OH)2(CO3) |
| 7.BC. | Wildcatite | CaFe3+Te6+O5(OH) |
| 7.BC. | Hagstromite | Pb8Cu2+(Te6+O6)2(CO3)Cl4 |
| 7.BC.05 | D'Ansite | Na21Mg(SO4)10Cl3 |
| 7.BC.07 | 'Apatelite' | Fe3(SO4)2(OH)5 · 0.5H2O |
| 7.BC.07 | 'Unnamed (Ba-Fe Vanadate)' | Ba, Fe, V, O, H |
| 7.BC.10 | Jarosite | KFe3+3(SO4)2(OH)6 |
| 7.BC.10 | Dorallcharite | TlFe3+3(SO4)2(OH)6 |
| 7.BC.10 | Argentojarosite | AgFe3+3(SO4)2(OH)6 |
| 7.BC.10 | Natroalunite | NaAl3(SO4)2(OH)6 |
| 7.BC.10 | Natrojarosite | NaFe3(SO4)2(OH)6 |
| 7.BC.10 | Beaverite-(Cu) | Pb(Fe3+2Cu)(SO4)2(OH)6 |
| 7.BC.10 | Beaverite-(Zn) | Pb(Fe3+2Zn)(SO4)2(OH)6 |
| 7.BC.10 | Walthierite | Ba0.5Al3(SO4)2(OH)6 |
| 7.BC.10 | Huangite | Ca0.5Al3(SO4)2(OH)6 |
| 7.BC.10 | 'Natroalunite-2c' | (Na,Ca0.5,K)Al3(SO4)2(OH)6 |
| 7.BC.10 | Alunite | KAl3(SO4)2(OH)6 |
| 7.BC.10 | Plumbojarosite | Pb0.5Fe3+3(SO4)2(OH)6 |
| 7.BC.10 | Karlseifertite | Pb(Ga2Ge)(AsO4)2(OH)6 |
| 7.BC.10 | Hydroniumjarosite | (H3O)Fe3+3(SO4)2(OH)6 |
| 7.BC.10 | Ammoniojarosite | (NH4)Fe3+3(SO4)2(OH)6 |
| 7.BC.10 | Osarizawaite | Pb(Al2Cu2+)(SO4)2(OH)6 |
| 7.BC.10 | Schlossmacherite | (H3O)Al3(SO4)2(OH)6 |
| 7.BC.15 | Ye'elimite | Ca4Al6(SO4)O12 |
| 7.BC.20 | Nabokoite | KCu7(SO4)5(Te4+O3)OCl |
| 7.BC.20 | Puninite | Na2Cu3O(SO4)3 |
| 7.BC.20 | Atlasovite | K(BiO)Cu6Fe3+(SO4)5O3Cl |
| 7.BC.25 | Chlorothionite | K2Cu(SO4)Cl2 |
| 7.BC.30 | Euchlorine | KNaCu3(SO4)3O |
| 7.BC.30 | Fedotovite | K2Cu3(SO4)3O |
| 7.BC.35 | Kamchatkite | KCu3(SO4)2OCl |
| 7.BC.40 | Piypite | K4Cu4O2(SO4)4 · (Na,Cu)Cl |
| 7.BC.45 | Alumoklyuchevskite | K3Cu3(Al,Fe3+)(SO4)4O2 |
| 7.BC.45 | Belousovite | KZn(SO4)Cl |
| 7.BC.45 | Klyuchevskite | K3Cu3(Fe3+,Al)(SO4)4O2 |
| 7.BC.47 | Müllerite | Pb2Fe3+(Te6+O6)Cl |
| 7.BC.50 | Caledonite | Pb5Cu2(SO4)3(CO3)(OH)6 |
| 7.BC.50 | Elasmochloite | Na3Cu6BiO4(SO4)5 |
| 7.BC.52 | Eleomelanite | (K2Pb)Cu4O2(SO4)4 |
| 7.BC.55 | Falgarite | K4(VO)3(SO4)5 |
| 7.BC.55 | Wherryite | Pb7Cu2(SO4)4(SiO4)2(OH)2 |
| 7.BC.57 | Krasheninnikovite | KNa2CaMg(SO4)3F |
| 7.BC.60 | Wulffite | K3NaCu4O2(SO4)4 |
| 7.BC.60 | Parawulffite | K5Na3Cu8O4(SO4)8 |
| 7.BC.60 | Mammothite | Pb6Cu4AlSb5+O2(OH)16Cl4(SO4)2 |
| 7.BC.62 | Shuvalovite | K2(Ca2Na)(SO4)3F |
| 7.BC.65 | Saccoite | Ca2Mn3+2F(OH)8 · 0.5(SO4) |
| 7.BC.65 | Linarite | PbCu(SO4)(OH)2 |
| 7.BC.65 | Therasiaite | (NH4)3KNa2Fe2+Fe3+(SO4)3Cl5 |
| 7.BC.65 | Franksousaite | PbCu(Se6+O4)(OH)2 |
| 7.BC.65 | Munakataite | Pb2Cu2(Se4+O3)(SO4)(OH)4 |
| 7.BC.65 | Schmiederite | Pb2Cu2(Se6+O4)(Se4+O3)(OH)4 |
| 7.BC.70 | Chenite | Pb4Cu(SO4)2(OH)6 |
| 7.BC.75 | Krivovichevite | Pb3Al(OH)6(SO4)(OH) |
| 7.BC.80 | Anhydrokainite | KMg(SO4)Cl |
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 Ammonioalunite
mindat.org URL:
https://www.mindat.org/min-203.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Ammonioalunite
Reference List:
Altaner, Stephen P., Fitzpatrick, Joan J., , M. Dennis Krohn, Bethke, Philip M., Hayba, Daniel O., Goss, James A., Brown, Zoe Ann (1988) Ammonium in alunites. American Mineralogist, 73 (1-2) 145-152
Localities for Ammonioalunite
Showing 15 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 | |
| Žáček et al. (1995) |
| Excalibur Mineral Corp. - Mineral News | |
| Zacek et al. (2019) | |
| Jirásek (2001) |
Germany | |
| Witzke et al. (2015) |
| Witzke et al. (1998) |
Hungary | |
| Szabó et al. (2015) |
Lebanon | |
| Kruszewski (2019) |
Poland | |
| Ciesielczuk et al. (2014) |
| Parafiniuk et al. (2009) |
| Kruszewski et al. (2020) |
USA | |
| Journal of Volcanology & Geothermal ... |
| Altaner et al. (1988) +1 other reference |
| Jour.Volcanology & Geothermal Res. ... +1 other reference |
| Castor et al. (2004) |
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Pécs-Vasas, Pécs District, Baranya County, Hungary