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Chlormagaluminite
A valid IMA mineral species
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About Chlormagaluminite
Formula:
Mg4Al2(OH)12Cl2 · 3H2O
Colour:
Colorless to yellow-brown; colorless in transmitted light
Lustre:
Vitreous, Pearly
Hardness:
1½ - 2½
Specific Gravity:
1.98 - 2.09
Crystal System:
Hexagonal
Member of:
Name:
For its composition: chloride, magnesium and aluminium.
Cl− and H2O are located in the interlayer.
Unique Identifiers
Mindat ID:
1018
Long-form identifier:
mindat:1:1:1018:0
IMA Classification of Chlormagaluminite
Classification of Chlormagaluminite
5.DA.45
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
5 : CARBONATES (NITRATES)
D : Carbonates with additional anions, with H2O
A : With medium-sized cations
10.6.10.1
10 : OXYHALIDES AND HYDROXYHALIDES
6 : AmBn(O,OH)pXq
10 : OXYHALIDES AND HYDROXYHALIDES
6 : AmBn(O,OH)pXq
12.1.4
12 : Carbonates with other anions
1 : Carbonates with halides
12 : Carbonates with other anions
1 : Carbonates with halides
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Cma | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Cma | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Physical Properties of Chlormagaluminite
Vitreous, Pearly
Transparency:
Translucent
Comment:
Pearly on cleavage surfaces
Colour:
Colorless to yellow-brown; colorless in transmitted light
Streak:
White
Hardness:
1½ - 2½ on Mohs scale
Comment:
Very soft
Cleavage:
Perfect
{0001}
{0001}
Density:
1.98 - 2.09 g/cm3 (Measured) 2.06 g/cm3 (Calculated)
Optical Data of Chlormagaluminite
Type:
Uniaxial (+)
RI values:
nω = 1.540(3) nε = 1.560(3)
Max. Birefringence:
δ = 0.020
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:
None to Very Low
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 Chlormagaluminite
Mindat Formula:
Mg4Al2(OH)12Cl2 · 3H2O
Element Weights:
Crystallography of Chlormagaluminite
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P63/mcm
Setting:
P63/mcm
Cell Parameters:
a = 5.268(3) Å, c = 15.297(8) Å
Ratio:
a:c = 1 : 2.904
Unit Cell V:
367.6 ų
Morphology:
Hexagonal dipyramids.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.67 Å | (100) |
| 1.839 Å | (100) |
| 2.34 Å | (90) |
| 2.17 Å | (90) |
| 1.526 Å | (90) |
| 1.496 Å | (90) |
| 3.86 Å | (80) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47g : [Halogen-bearing surface weathering minerals] |
Type Occurrence of Chlormagaluminite
General Appearance of Type Material:
Hexagonal dipyramids to more than 1 mm.
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, number 82771.
Geological Setting of Type Material:
Skarn.
Associated Minerals at Type Locality:
Synonyms of Chlormagaluminite
Other Language Names for Chlormagaluminite
Relationship of Chlormagaluminite to other Species
Member of:
Other Members of Quintinite Group:
| Caresite | Fe2+4Al2(OH)12[CO3] · 3H2O | Trig. 32 : P3112 |
| Charmarite | Mn2+4Al2(OH)12[CO3] · 3H2O | Hex. |
| Comblainite | Ni4Co2(OH)12[CO3] · 3H2O | Trig. |
| Liudongshengite | Zn4Cr2(OH)12(CO3) · 3H2O | Trig. 3m(32/m) : R3m |
| Quintinite | Mg4Al2(OH)12(CO3) · 3H2O | Hex. 622 : P6322 |
| 'Unnamed (Zn-analogue of Chlormagaluminite)' | Zn4Al2(OH)12Cl2 · 2H2O | |
| Zaccagnaite | Zn4Al2(OH)12[CO3] · 3H2O | Hex. |
Related Minerals - Strunz-mindat Grouping
| 5.DA. | Alexkhomyakovite | K6(Ca2Na)(CO3)5Cl · 6H2O |
| 5.DA. | Amoraite | Ca12Al6(OH)36(CO3)2(SO3) · 15H2O |
| 5.DA.05 | Dypingite | Mg5(CO3)4(OH)2 · 5H2O |
| 5.DA.05 | 'UM1986-10-CO:ClHMgMnZn (also called Mineral F, Dunn, 1995)' | Mg5(Zn,Mn)3(CO3)2(OH,Cl)12 · H2O |
| 5.DA.05 | 'UM1987-01-CO:HMgS' | Mg4(CO3)2(OH)4 · 6H2O ? |
| 5.DA.05 | Giorgiosite | Mg5(CO3)4(OH)2 · 5-6H2O |
| 5.DA.05 | Hydromagnesite | Mg5(CO3)4(OH)2 · 4H2O |
| 5.DA.05 | Widgiemoolthalite | Ni5(CO3)4(OH)2 · 5H2O |
| 5.DA.10 | Artinite | Mg2(CO3)(OH)2 · 3H2O |
| 5.DA.10 | Chlorartinite | Mg2(CO3)(OH)Cl · 2H2O |
| 5.DA.10 | Indigirite | Mg2Al2(CO3)4(OH)2 · 15H2O |
| 5.DA.15 | Zaratite | Ni3(CO3)(OH)4 · 4H2O ? |
| 5.DA.15 | Otwayite | Ni2(CO3)(OH)2 · H2O |
| 5.DA.20 | Kambaldaite | NaNi4(CO3)3(OH)3 · 3H2O |
| 5.DA.25 | Callaghanite | Cu2Mg2(CO3)(OH)6 · 2H2O |
| 5.DA.30 | Claraite | (Cu,Zn)15(CO3)4(AsO4)2(SO4)(OH)14 · 7H2O |
| 5.DA.35 | Hydroscarbroite | Al14(CO3)3(OH)36 · nH2O |
| 5.DA.35 | Scarbroite | Al5(CO3)(OH)13 · 5H2O |
| 5.DA.40 | Karchevskyite | Mg18Al9(OH)54Sr2(CO3)9(H2O)6(H3O)5 |
| 5.DA.40 | 'UM1987-05-OH:AlCMg' | Mg4Al2(OH)12(CO3,SO4) · 3H2O |
| 5.DA.40 | Quintinite | Mg4Al2(OH)12(CO3) · 3H2O |
| 5.DA.40 | Charmarite | Mn2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.40 | Caresite | Fe2+4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Hydrotalcite-2H' | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | 'Stichtite-2H' | Mg6(Cr,Al)2(CO3)(OH)16 · 4H2O |
| 5.DA.45 | Brugnatellite | Mg6Fe3+(CO3)(OH)13 · 4H2O |
| 5.DA.45 | Zaccagnaite | Zn4Al2(OH)12[CO3] · 3H2O |
| 5.DA.45 | 'Pyroaurite-2H' | Mg6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.45 | Liudongshengite | Zn4Cr2(OH)12(CO3) · 3H2O |
| 5.DA.50 | Pyroaurite | Mg6Fe3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Takovite | Ni6Al2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Reevesite | Ni6Fe3+2(OH)16(CO3) · 4H2O |
| 5.DA.50 | Kaznakhtite | Ni6Co3+2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Comblainite | Ni4Co2(OH)12[CO3] · 3H2O |
| 5.DA.50 | Marioantofilliite | [Cu4Al2(OH)12](CO3) · 3H2O |
| 5.DA.50 | Hydrotalcite | Mg6Al2(CO3)(OH)16 · 4H2O |
| 5.DA.50 | Stichtite | Mg6Cr3+2(OH)16[CO3] · 4H2O |
| 5.DA.50 | Desautelsite | Mg6Mn3+2(OH)16[CO3] · 4H2O |
| 5.DA.55 | Coalingite | Mg10Fe3+2(OH)24[CO3] · 2H2O |
| 5.DA.55 | Akopovaite | Al4Li2(OH)12(CO3)(H2O)3 |
| 5.DA.60 | Šlikite | Zn2Mg(CO3)2(OH)2 · 4H2O |
| 5.DA.65 | Marklite | Cu5(CO3)2(OH)6 · 6H2O |
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 Chlormagaluminite
mindat.org URL:
https://www.mindat.org/min-1018.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Chlormagaluminite
Reference List:
Dunn, P. J.; Cabri, L. J.; Clark, A. M.; Fleischer, M. (1983) New mineral names. American Mineralogist, 68 (7-8). 849-852
Mills, S. J.; Christy, A. G.; Génin, J.-M. R.; Kameda, T.; Colombo, F. (2012) Nomenclature of the hydrotalcite supergroup: natural layered double hydroxides. Mineralogical Magazine, 76 (5). 1289-1336 doi:10.1180/minmag.2012.076.5.10
Oestreicher, Víctor, Jobbágy, Matías (2013) One Pot Synthesis of Mg2Al(OH)6Cl·1.5H2O Layered Double Hydroxides: The Epoxide Route. Langmuir, 29. 12104-12109 doi:10.1021/la402260m
Oestreicher, Víctor, Fábregas, Ismael, Jobbágy, Matías (2014) One-Pot Epoxide-Driven Synthesis of M2Al(OH)6Cl·1.5H2O Layered Double Hydroxides: Precipitation Mechanism and Relative Stabilities. The Journal of Physical Chemistry C, 118 (51). 30274-30281 doi:10.1021/jp510341q
Localities for Chlormagaluminite
Showing 4 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.
Canada | |
| McDonald et al. (1994) |
Czech Republic | |
| Houzar et al. (2008) |
Russia (TL) | |
| Kashaev et al. (1982) +3 other references |
| Mazurov et al. (2007) |
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Kapaevskaya Pipe, Middle Angara River, Irkutsk Oblast, Russia