Aluminocoquimbite
A valid IMA mineral species
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About Aluminocoquimbite
Formula:
Al2Fe2(SO4)6(H2O)12 · 6H2O
formerly given as FeAl(SO4)3.9H2O; in course of the IMA redefinition and to better address its relation to coquimbite, the newly-accepted formula is a multiplication of the former.
Colour:
Colourless to pale pink
Lustre:
Vitreous
Specific Gravity:
2.03
Crystal System:
Trigonal
Member of:
Name:
Named for the relation to coquimbite and its elevated Al content.
Visually indistinguishable from coquimbite.
The structure differs from that of coquimbite in occuppancy of the three non-equivalent octahedral metal sites, and content of the coordination sphere of these three sites. M(1) and M(2) sites are occupied by Fe, surrounded exclusively by oxygen atoms belonging to the sulphate groups. M(3) site is occupied by Al, which forms isolated Al(H2O)6 octahedron. Fe(1) and Fe(2) octahedra share corners with sulfate tetrahedra; these Fe sites alternate to form infinite Fe(SO4)3 columns along [001], resembling columns in ferrinatrite. There is a hydrogen-bond linkage between these columns and Al-bearing octahedra, which provides cages hosting six water molecules. Interestingly, as in coquimbite, these water molecules are arranged in a cyclohexane-like chair motif.
The structure differs from that of coquimbite in occuppancy of the three non-equivalent octahedral metal sites, and content of the coordination sphere of these three sites. M(1) and M(2) sites are occupied by Fe, surrounded exclusively by oxygen atoms belonging to the sulphate groups. M(3) site is occupied by Al, which forms isolated Al(H2O)6 octahedron. Fe(1) and Fe(2) octahedra share corners with sulfate tetrahedra; these Fe sites alternate to form infinite Fe(SO4)3 columns along [001], resembling columns in ferrinatrite. There is a hydrogen-bond linkage between these columns and Al-bearing octahedra, which provides cages hosting six water molecules. Interestingly, as in coquimbite, these water molecules are arranged in a cyclohexane-like chair motif.
Unique Identifiers
Mindat ID:
40001
Long-form identifier:
mindat:1:1:40001:1
IMA Classification of Aluminocoquimbite
Approved
IMA Formula:
Al2Fe2(SO4)6(H2O)12 · 9H2O
Approval year:
2009
First published:
2010
Approval history:
redefinition code: IMA-19F
Classification of Aluminocoquimbite
7.CB.50
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
29.8.8.
29 : HYDRATED ACID AND NORMAL SULFATES
8 : A2(XO4)3·H2O
29 : HYDRATED ACID AND NORMAL SULFATES
8 : A2(XO4)3·H2O
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 |
|---|---|---|
| Acoq | 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 Aluminocoquimbite
Vitreous
Colour:
Colourless to pale pink
Streak:
White
Cleavage:
Imperfect/Fair
On {101}.
On {101}.
Density:
2.03(1) g/cm3 (Measured) 2.044 g/cm3 (Calculated)
Comment:
Calculated value based on the empirical formula.
Optical Data of Aluminocoquimbite
Type:
Uniaxial (+)
RI values:
nω = 1.530 nε = 1.560
Max. Birefringence:
δ = 0.000
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
Chemistry of Aluminocoquimbite
Mindat Formula:
Al2Fe2(SO4)6(H2O)12 · 6H2O
formerly given as FeAl(SO4)3.9H2O; in course of the IMA redefinition and to better address its relation to coquimbite, the newly-accepted formula is a multiplication of the former.
formerly given as FeAl(SO4)3.9H2O; in course of the IMA redefinition and to better address its relation to coquimbite, the newly-accepted formula is a multiplication of the former.
Element Weights:
Crystallography of Aluminocoquimbite
Crystal System:
Trigonal
Class (H-M):
3m (3 2/m) - Hexagonal Scalenohedral
Space Group:
P3 1c
Cell Parameters:
a = 10.7065(7) Å, c = 17.3077(11) Å
Ratio:
a:c = 1 : 1.617
Unit Cell V:
1718.2 ų
Z:
4
Morphology:
Tabular to prismatic. The prevailing forms of the crystals are the pinacoid and hexagonal prisms of first and second order.
Twinning:
None observed.
Comment:
Space group identical with that of coquimbite, but structure is different.
Crystal Structure
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0006337 | Aluminocoquimbite | Demartin F, Castellano C, Gramaccioli C M, Campostrini I (2010) Aluminum-for-iron substitution, hydrogen bonding, and a novel structure-type in coquimbite-like minerals The Canadian Mineralogist 48 323-333 | 2010 | Alum Grotto, Vulcano, Aeolian Islands, Sicily, Italy | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.251 Å | (100) |
| 5.310 Å | (110) |
| 3.152 Å | (43) |
| 4.087 Å | (33) |
| 1.765 Å | (20) |
| 2.112 Å | (17) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 45a : [Sulfates, arsenates, selenates, antimonates] | |
| 47a : [Near-surface hydration of prior minerals] | |
| 47b : [Sulfates and sulfites] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Type Occurrence of Aluminocoquimbite
General Appearance of Type Material:
Prisms, up to 0.5 mm.
Place of Conservation of Type Material:
Department of Structural Chemistry and Inorganic Sterochemistry, University of Milan, Italy, number 2009-03.
Geological Setting of Type Material:
Low-temperature (below 100 °C) fumaroles.
Associated Minerals at Type Locality:
Synonyms of Aluminocoquimbite
Other Language Names for Aluminocoquimbite
Relationship of Aluminocoquimbite to other Species
Member of:
Other Members of Coquimbite Group:
| Coquimbite | AlFe3(SO4)6(H2O)12 · 6H2O | Trig. 3m (3 2/m) : P3 1c |
| Paracoquimbite | Fe4(SO4)6(H2O)12 · 6H2O | Trig. 3 : R3 |
Common Associates
Associated Minerals Based on Photo Data:
| 2 photos of Aluminocoquimbite associated with Pickeringite | MgAl2(SO4)4 · 22H2O |
| 1 photo of Aluminocoquimbite associated with Metavoltine | K2Na6Fe2+Fe3+6O2(SO4)12 · 18H2O |
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 | (Co,Mn,Ni)SO4 · 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 | Mn(SO4) · 6H2O |
| 7.CB.25 | Nickelhexahydrite | Ni(SO4) · 6H2O |
| 7.CB.25 | Hexahydrite | MgSO4 · 6H2O |
| 7.CB.25 | Bianchite | Zn(SO4) · 6H2O |
| 7.CB.25 | Moorhouseite | Co(SO4) · 6H2O |
| 7.CB.25 | Ferrohexahydrite | FeSO4 · 6H2O |
| 7.CB.30 | Retgersite | NiSO4 · 6H2O |
| 7.CB.35 | Zincmelanterite | (Zn,Cu,Fe)SO4 · 7H2O |
| 7.CB.35 | Melanterite | Fe2+(H2O)6SO4 · H2O |
| 7.CB.35 | Alpersite | (Mg,Cu)(SO4) · 7H2O |
| 7.CB.35 | Bieberite | CoSO4 · 7H2O |
| 7.CB.35 | Boothite | CuSO4 · 7H2O |
| 7.CB.35 | Mallardite | MnSO4 · 7H2O |
| 7.CB.40 | Epsomite | MgSO4 · 7H2O |
| 7.CB.40 | Goslarite | ZnSO4 · 7H2O |
| 7.CB.40 | Morenosite | NiSO4 · 7H2O |
| 7.CB.45 | Meta-alunogen | Al2(SO4)3 · 12H2O |
| 7.CB.45 | Alunogen | Al2(SO4)3 · 17H2O |
| 7.CB.50 | Lazaridisite | 3CdSO4 · 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 | (Zn,Fe2+,Mn2+)Al2(SO4)4 · 22H2O |
| 7.CB.85 | Halotrichite | FeAl2(SO4)4 · 22H2O |
| 7.CB.85 | Apjohnite | Mn2+Al2(SO4)4 · 22H2O |
| 7.CB.85 | Redingtonite | (Fe2+,Mg,Ni)(Cr,Al)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 | (Co,Mg,Ni)Al2(SO4)4 · 22H2O |
| 7.CB.90 | Meridianiite | MgSO4 · 11H2O |
Fluorescence of Aluminocoquimbite
Not fluorescent.
Other Information
Notes:
Not hygroscopic and is stable in open air.
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 Aluminocoquimbite
mindat.org URL:
https://www.mindat.org/min-40001.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Aluminocoquimbite
Reference List:
Demartin, F., Castellano, C., Gramaccioli, C. M., Campostrini, I. (2010) ALUMINUM-FOR-IRON SUBSTITUTION, HYDROGEN BONDING, AND A NOVEL STRUCTURE-TYPE IN COQUIMBITE-LIKE MINERALS. The Canadian Mineralogist, 48 (2) 323-333 doi:10.3749/canmin.48.2.323
Demartin, F., Castellano, C., Gramaccioli, C. M., Campostrini, I. (2010) Aluminocoquimbite, AlFe(SO4)3 · 9H2O, a new aluminum iron sulfate from Grotta dell'Allume, Vulcano, Aeolian Islands, Italy. The Canadian Mineralogist, 48 (6) 1465-1468 doi:10.3749/canmin.48.5.1465
Majzlan, Juraj, Ðorđević, Tamara, Kolitsch, Uwe, Schefer, Jürg (2010) Hydrogen bonding in coquimbite, nominally Fe2(SO4)3·9H2O, and the relationship between coquimbite and paracoquimbite. Mineralogy and Petrology, 100 (3) 241-248 doi:10.1007/s00710-010-0128-4
Localities for Aluminocoquimbite
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.
Italy | |
| Russo et al. (2017) |
| Russo et al. (2017) | |
| Demartin et al. (2010) +2 other references |
Lebanon | |
| |
Peru | |
| Tyc et al. (2022) |
Portugal | |
| Oliveira et al. (2024) |
USA | |
| Joe Marty (2015) |
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Grotta dell'Allume, Faraglione Nico, Faraglioni di Levante, Porto Levante, Vulcano Island, Lipari, Eolie Islands, Metropolitan City of Messina, Sicily, Italy