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Meta-alunogen
A valid IMA mineral species - grandfathered - questionable
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Formula:
Al2(SO4)3 · 12H2O
Colour:
White, pale yellow
Lustre:
Waxy, Pearly
Specific Gravity:
2.85 (Calculated)
Crystal System:
Orthorhombic
Name:
Named for being a lower hydrate counterpart of alunogen.
The lower hydrate counterpart of alunogen. Compare also Unnamed (Al Sulphate-Hydrate), 'UM1987-13-SO:AlH' and 'UM1976-22-SO:AlFeH'.
Unique Identifiers
Mindat ID:
2660
Long-form identifier:
mindat:1:1:2660:0
IMA Classification of Meta-alunogen
Approved, 'Grandfathered' (first described prior to 1959), Questionable
IMA Formula:
Al2(S6+O4)3·14H2O
Classification of Meta-alunogen
7.CB.45
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
B : With only medium-sized cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
B : With only medium-sized cations
29.8.7.1
29 : HYDRATED ACID AND NORMAL SULFATES
8 : A2(XO4)3·H2O
29 : HYDRATED ACID AND NORMAL SULFATES
8 : A2(XO4)3·H2O
25.6.6
25 : Sulphates
6 : Sulphates of Al and Tl
25 : Sulphates
6 : Sulphates of Al and Tl
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 |
|---|---|---|
| Malg | 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 Meta-alunogen
Waxy, Pearly
Transparency:
Translucent
Colour:
White, pale yellow
Cleavage:
Perfect
{010}
{010}
Density:
2.85 g/cm3 (Calculated)
Optical Data of Meta-alunogen
Type:
Biaxial (+)
RI values:
nα = 1.469 nβ = 1.473 nγ = 1.491
Max. Birefringence:
δ = 0.022
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 (negative)
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.
No measured or calculated 2V is on file for this mineral, so the value used here (51°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
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.
No measured or calculated 2V is on file for this mineral, so the value used here (51°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
relatively weak
Comments:
2V(meas.) = Large.
Chemistry of Meta-alunogen
Mindat Formula:
Al2(SO4)3 · 12H2O
Element Weights:
Elements listed:
Crystallography of Meta-alunogen
Crystal System:
Orthorhombic
Cell Parameters:
a = 12.25 Å, b = 13.95 Å, c = 15.95 Å
Ratio:
a:b:c = 0.878 : 1 : 1.143
Unit Cell V:
2,725.66 ų (Calculated from Unit Cell)
Comment:
Point Group: n.d. Space Group: n.d. synthetic
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.071 Å | (100) |
| 12.20 Å | (26) |
| 6.114 Å | (11) |
| 3.860 Å | (9) |
| 4.208 Å | (7) |
| 3.990 Å | (5) |
| 3.024 Å | (4) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 25 : Evaporites (prebiotic) | |
| Stage 7: Great Oxidation Event | <2.4 |
| 46 : Near-surface hydrothermal alteration of minerals (see also #22) |
Type Occurrence of Meta-alunogen
Associated Minerals at Type Locality:
Other Language Names for Meta-alunogen
German:Meta-Alunogen
Common Associates
Associations Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
| 7.CB. | Sarvodaite | Al2(SO4)3 · 5H2O |
| 7.CB.02 | Voudourisite | CdSO4 · H2O |
| 7.CB.05 | Szmikite | MnSO4 · H2O |
| 7.CB.05 | Szomolnokite | FeSO4 · H2O |
| 7.CB.05 | Cobaltkieserite | CoSO4 · H2O |
| 7.CB.05 | Dwornikite | Ni(SO4) · H2O |
| 7.CB.05 | Kieserite | MgSO4 · H2O |
| 7.CB.05 | Poitevinite | (Cu,Fe)SO4 · H2O |
| 7.CB.05 | Gunningite | ZnSO4 · H2O |
| 7.CB.07 | Sanderite | MgSO4 · 2H2O |
| 7.CB.10 | Bonattite | CuSO4 · 3H2O |
| 7.CB.12 | Belogubite | CuZn(SO4)2 · 10H2O |
| 7.CB.15 | Drobecite | CdSO4 · 4H2O |
| 7.CB.15 | Aplowite | CoSO4 · 4H2O |
| 7.CB.15 | Cranswickite | MgSO4 · 4H2O |
| 7.CB.15 | Rozenite | FeSO4 · 4H2O |
| 7.CB.15 | Starkeyite | MgSO4 · 4H2O |
| 7.CB.15 | Ilesite | Mn2+(SO4) · 4H2O |
| 7.CB.15 | Boyleite | ZnSO4 · 4H2O |
| 7.CB.20 | Siderotil | FeSO4 · 5H2O |
| 7.CB.20 | Jôkokuite | MnSO4 · 5H2O |
| 7.CB.20 | Pentahydrite | MgSO4 · 5H2O |
| 7.CB.20 | Chalcanthite | CuSO4 · 5H2O |
| 7.CB.25 | Chvaleticeite | Mn2+(H2O)6(SO4) |
| 7.CB.25 | Nickelhexahydrite | Ni2+(H2O)6(SO4) |
| 7.CB.25 | Hexahydrite | Mg(H2O)6(SO4) |
| 7.CB.25 | Bianchite | Zn(H2O)6(SO4) |
| 7.CB.25 | Moorhouseite | Co2+(H2O)6(SO4) |
| 7.CB.25 | Ferrohexahydrite | Fe2+(H2O)6(SO4) |
| 7.CB.30 | Retgersite | NiSO4 · 6H2O |
| 7.CB.35 | Zincmelanterite | Zn(H2O)6(SO4) · H2O |
| 7.CB.35 | Melanterite | Fe2+(H2O)6(SO4) · H2O |
| 7.CB.35 | Alpersite | (Mg,Cu2+)(H2O)6(SO4) · H2O |
| 7.CB.35 | Bieberite | Co2+(H2O)6(SO4) · H2O |
| 7.CB.35 | Boothite | Cu2+(H2O)6(SO4) · H2O |
| 7.CB.35 | Mallardite | Mn2+(H2O)6(SO4) · H2O |
| 7.CB.40 | Epsomite | MgSO4 · 7H2O |
| 7.CB.40 | Goslarite | ZnSO4 · 7H2O |
| 7.CB.40 | Morenosite | NiSO4 · 7H2O |
| 7.CB.45 | Alunogen | Al2(SO4)3 · 17H2O |
| 7.CB.50 | Aluminocoquimbite | Al2Fe2(SO4)6(H2O)12 · 6H2O |
| 7.CB.50 | Lazaridisite | Cd3(SO4)3 · 8H2O |
| 7.CB.52 | Pararaisaite | CuMg[Te6+O4(OH)2] · 6H2O |
| 7.CB.55 | Paracoquimbite | Fe4(SO4)6(H2O)12 · 6H2O |
| 7.CB.55 | Rhomboclase | (H5O2)Fe3+(SO4)2 · 2H2O |
| 7.CB.55 | Raisaite | CuMg[Te6+O4(OH)2] · 6H2O |
| 7.CB.55 | Coquimbite | AlFe3(SO4)6(H2O)12 · 6H2O |
| 7.CB.57 | 'Caichengyunite' | Fe2+3Al2(SO4)6 · 30H2O |
| 7.CB.60 | Kornelite | Fe2(SO4)3 · 7H2O |
| 7.CB.65 | Quenstedtite | Fe2(SO4)3 · 11H2O |
| 7.CB.70 | Lausenite | Fe2(SO4)3 · 5H2O |
| 7.CB.75 | Römerite | Fe2+Fe3+2(SO4)4 · 14H2O |
| 7.CB.75 | Lishizhenite | ZnFe2(SO4)4 · 14H2O |
| 7.CB.80 | Ransomite | CuFe2(SO4)4 · 6H2O |
| 7.CB.85 | Dietrichite | ZnAl2(SO4)4 · 22H2O |
| 7.CB.85 | Halotrichite | Fe2+Al2(SO4)4 · 22H2O |
| 7.CB.85 | Apjohnite | Mn2+Al2(SO4)4 · 22H2O |
| 7.CB.85 | Redingtonite | Fe2+Cr3+2(SO4)4 · 22H2O |
| 7.CB.85 | Pickeringite | MgAl2(SO4)4 · 22H2O |
| 7.CB.85 | Bílinite | Fe2+Fe3+2(SO4)4 · 22H2O |
| 7.CB.85 | Wupatkiite | Co2+Al2(SO4)4 · 22H2O |
| 7.CB.90 | Meridianiite | MgSO4 · 11H2O |
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 Meta-alunogen
mindat.org URL:
https://www.mindat.org/min-2660.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Meta-alunogen
Reference List:
Kahlenberg, Volker, Braun, Doris E., Krüger, Hannes, Schmidmair, Daniela, Orlova, Maria (2017) Temperature- and moisture-dependent studies on alunogen and the crystal structure of meta-alunogen determined from laboratory powder diffraction data. Physics and Chemistry of Minerals, 44 (2) 95-107 doi:10.1007/s00269-016-0840-7
Localities for Meta-alunogen
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.
Chile | |
| SEM-EDS |
| Collected by Samuel Gordon in 1938. Xrd ... |
| S. G. Gordon (1942) +1 other reference |
Costa Rica | |
| Rodríguez et al. (2017) |
Lebanon | |
| Kruszewski (2019) |
New Zealand | |
| Martin et al. (1999) |
| Rod Martin et al. (NZ) |
| Krupp et al. (1987) |
Poland | |
| Kruszewski et al. (2020) |
Russia | |
| Kudrin et al. (2021) |
Slovakia | |
| Duda |
Spain | |
| Calvo Rebollar (2014) |
USA | |
| Anthony et al. (1995) |
| Chemical Geology Volume 215 |
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