Armangite Mineral Data

General Armangite Information

Chemical Formula:

Mn26As+++18O50(OH)4(CO3)

Composition:

Molecular Weight = 3,704.99 gm

Manganese 38.55 % Mn 49.78 % MnO

Arsenic 36.40 % As 48.06 % As₂O₃

Hydrogen 0.11 % H 0.97 % H₂O

Carbon 0.32 % C 1.19 % CO₂

Oxygen 24.61 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₂₆As₁₈O₅₀(OH)₄(CO₃)

Environment:

On a museum specimen collected from a metamorphosed Fe-Mn deposit.

IMA Status:

Valid Species (Pre-IMA) 1920

Locality:

Langban, Vï¿½armland, Sweden. Link to MinDat.org Location Data.

Name Origin:

Named for Arsenic and MANGanese in the composition.

Name Pronunciation:

Armangite + Pronunciation

Synonym:

ICSD 100555

PDF 19-780

Armangite Image

Images:

Armangite

Comments: Black crystals of armangite on matrix.
Location: Langban, Varmland, Sweden.. Scale: Specimen Size 2.5 x 4 cm.
© John Veevaert

Armangite Crystallography

Axial Ratios:

a:c = 1:0.65636

Cell Dimensions:

a = 13.491, c = 8.855, Z = 1; V = 1,395.75 Den(Calc)= 4.41

Crystal System:

Trigonal - Rhombohedral H-M Symbol ( 3) Space Group: P 3

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.774(1), 2.952(0.55), 2.924(0.38),

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Forms: ( 1 1 0) ( 2 2 1) ( 0 0 1)

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Physical Properties of Armangite

Cleavage:

{0001} Good

Color:

Black.

Density:

4.43

Diaphaneity:

Transparent to Opaque

Hardness:

4 - Fluorite

Streak:

brown

Optical Properties of Armangite

Gladstone-Dale:

CI meas= -0.041 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.046 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2268,KPDmeas= 0.2257,KC= 0.2168
Ncalc = 1.96

Optical Data:

Uniaxial (-), e=1.99, w=2.01, bire=0.0200.

Calculated Properties of Armangite

Electron Density:

Bulk Density (Electron Density)=4.09 gm/cc
note: Specific Gravity of Armangite =4.43 gm/cc.

Fermion Index:

Fermion Index = 0.0001539734
Boson Index = 0.9998460266

Photoelectric:

PE_Armangite= 35.79 barns/electron
U=PE_Armangite x rElectron Density= 146.37 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Armangite is Not Radioactive

Armangite Classification

Dana Class:

46.02.07.01 (46)Basic or Halogen-Containing Antimonites, Arsenites and Phosphites

(46.02)with miscellaneous formulae

(46.02.07)Dana Group

46.02.07.01 Armangite Mn26As18O50(OH)4(CO3) P 3 3

Strunz Class:

04.JB.20 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.J - Arsenites, Antimonites, Bismuthites, Sulfites,

04.JB -Arsenites, antimonites, bismuthites; with additional anions, without H2O

04.JB.20 Armangite Mn26As18O50(OH)4(CO3) P 3 3

Other Armangite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Armangite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

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Print or Cut-and-Paste your Armangite Specimen Label here :

Armangite

Mn26As+++18O50(OH)4(CO3)
Dana No: 46.02.07.01 Strunz No: 04.JB.20
Locality:

Notes:

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