Armangite
A valid IMA mineral species - grandfathered
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About Armangite
Formula:
Mn2+26(AsO3)14(HAsO3)4(CO3)
Colour:
Black to pale brown; yellow to brown in transmitted light
Hardness:
4
Specific Gravity:
4.43
Crystal System:
Trigonal
Name:
In allusion to the composition, containing ARsenic and MANGanese.
This page provides mineralogical data about Armangite.
Unique Identifiers
Mindat ID:
342
Long-form identifier:
mindat:1:1:342:9
IMA Classification of Armangite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mn2+26As3+18O50(CO3)(OH)4
Classification of Armangite
4.JB.20
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
B : Arsenites, antimonites, bismuthites; with additional anions, without H2O
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
B : Arsenites, antimonites, bismuthites; with additional anions, without H2O
46.2.7.1
46 : ANTIMONITES AND ARSENITES CONTAINING HYDROXYL OR HALOGEN
2 : Miscellaneous
46 : ANTIMONITES AND ARSENITES CONTAINING HYDROXYL OR HALOGEN
2 : Miscellaneous
23.17
23 : Arsenites
23 : Arsenites
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 |
|---|---|---|
| Amg | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Arm | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Armangite
Transparency:
Opaque
Colour:
Black to pale brown; yellow to brown in transmitted light
Streak:
Brown
Hardness:
4 on Mohs scale
Cleavage:
Imperfect/Fair
Fair to poor on {0001}.
Fair to poor on {0001}.
Density:
4.43 g/cm3 (Measured) 4.406 g/cm3 (Calculated)
Optical Data of Armangite
Type:
Uniaxial (-)
RI values:
nω = 2.01 nε = 1.99
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:
Moderate
Pleochroism:
Non-pleochroic
Chemistry of Armangite
Mindat Formula:
Mn2+26(AsO3)14(HAsO3)4(CO3)
Element Weights:
Common Impurities:
Fe,Pb,Sb
Crystallography of Armangite
Crystal System:
Trigonal
Class (H-M):
3 - Rhombohedral
Space Group:
P3
Cell Parameters:
a = 13.491 Å, c = 8.855 Å
Ratio:
a:c = 1 : 0.656
Unit Cell V:
1,395.75 ų (Calculated from Unit Cell)
Z:
1
Morphology:
Crystals short hexagonal prisms, terminated by a trigonal pyramid
Twinning:
on {1120}.
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) |
|---|---|---|---|---|---|---|---|
| 0000738 | Armangite | Moore P B, Araki T (1979) Armangite, Mn26[As6(OH)4O14][As6O18]2[CO3], a fluorite derivative structure American Mineralogist 64 748-757 |  | 1979 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.762 Å | (100) |
| 2.94 Å | (70) |
| 2.428 Å | (70) |
| 1.759 Å | (60) |
| 3.92 Å | (50) |
| 1.676 Å | (50) |
| 1.459 Å | (50) |
Comments:
Material from Langban, Sweden (ICDD 19-780)
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits |
Type Occurrence of Armangite
General Appearance of Type Material:
tiny prismatic crystals
Place of Conservation of Type Material:
Swedish Museum of Natural History, Stockholm, Sweden (Flink U71);
U.S. National Museum of Natural History, Washington, D.C., USA (No. R5795)
U.S. National Museum of Natural History, Washington, D.C., USA (No. R5795)
Geological Setting of Type Material:
Museum specimen collected from a metamorphosed Fe-Mn deposit
Associated Minerals at Type Locality:
Other Language Names for Armangite
Common Associates
Associations Based on Photo Data:
| 1 photo of Armangite associated with Magnussonite | Mn2+10(As3+O3)6(OH,Cl)2 |
| 1 photo of Armangite associated with Native Lead | Pb |
| 1 photo of Armangite associated with Baryte | BaSO4 |
Related Minerals - Strunz-mindat Grouping
| 4.JB. | Cuyaite | Ca2Mn3+As3+14O24Cl |
| 4.JB. | Brattforsite | Mn19(AsO 3)12Cl2 |
| 4.JB.05 | Fetiasite | (Fe3+,Fe2+,Ti)3(As2O5)O2 |
| 4.JB.10 | Manganarsite | Mn3(As2O4)(OH)4 |
| 4.JB.15 | 'UM1984-09-AsO:ClHMn' | Mn10As6O18(OH)Cl |
| 4.JB.15 | Magnussonite | Mn2+10(As3+O3)6(OH,Cl)2 |
| 4.JB.25 | Nanlingite | Na(Ca5Li)Mg12(AsO3)2[Fe(AsO3)6]F14 |
| 4.JB.30 | Asbecasite | Ca3(Ti,Sn4+)Be2(AsO3)6(SiO4)2 |
| 4.JB.35 | Stenhuggarite | CaFeSb(AsO3)2O |
| 4.JB.40 | Trigonite | Pb3Mn2+(AsO3)2(HAsO3) |
| 4.JB.45 | Finnemanite | Pb5(AsO3)3Cl |
| 4.JB.50 | Gebhardite | Pb8(As2O5)2OCl6 |
| 4.JB.55 | Graeserite | Fe3+4Ti3As3+O13(OH) |
| 4.JB.55 | Tomichite | (V,Fe)4Ti3AsO13(OH) |
| 4.JB.55 | Derbylite | Fe3+4Ti3Sb3+O13(OH) |
| 4.JB.60 | Hemloite | (Ti,V3+,Fe3+,Al)12(As3+,Sb3+)2O23(OH) |
| 4.JB.65 | Freedite | Cu+Pb8(AsO3)2O3Cl5 |
| 4.JB.70 | Georgiadesite | Pb4(As3+O3)Cl4(OH) |
| 4.JB.75 | Szklaryite | ◻Al6BAs3+3O15 |
| 4.JB.75 | Ekatite | (Fe3+,Fe2+,Zn)12(AsO3)6(AsO3,HSiO4)2(OH)6 |
| 4.JB.85 | Lepageite | Mn2+3(Fe3+7Fe2+4)O3[Sb3+5As3+8O34] |
| 4.JB.90 | Bianchiniite | Ba2(TiV)(As2O5)2OF |
Other Information
Notes:
Readily soluble in HCl, separating As2O3, which dissolves on dilution and warming.
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 Armangite
mindat.org URL:
https://www.mindat.org/min-342.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Armangite
Reference List:
Aminoff, G., Mauzelius, R. (1920) Armangite, a new arsenite from Långbanshyttan. Geologiska Föreningen i Stockholm Förhandlingar, 42 (5) 301-309 doi:10.1080/11035892009444471
Larsen, E.S.; Berman, H. (1934) The microscopic determination of the nonopaque minerals. Bulletin of the US Geological Survey Vol. 848. US Geological Survey p.1-266. doi:10.3133/b848 p.91
Localities for Armangite
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.
Sweden (TL) | |
| Aminoff et al. (1920) +2 other references |
| Gatedal (n.d.) +1 other reference | |
| Nysten (1987) |
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Långban Mine, Långban Ore District, Filipstad, Värmland County, Sweden