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Armbrusterite Mineral Data

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General Armbrusterite Information

Help on Chemical  Formula: Chemical Formula: K5Na6Mn+++Mn++14[Si9O22]4(OH)10•4H2O
Help on Composition: Composition: Molecular Weight = 3,806.38 gm
   Potassium   5.17 %  K     6.22 % K2O
   Sodium      3.96 %  Na    5.33 % Na2O
   Calcium     0.19 %  Ca    0.27 % CaO
   Magnesium   0.11 %  Mg    0.19 % MgO
   Titanium    0.03 %  Ti    0.04 % TiO2
   Manganese  20.02 %  Mn   23.97 % MnO /  2.09 % Mn2O3
   Aluminum    0.02 %  Al    0.04 % Al2O3
   Zinc        0.15 %  Zn    0.19 % ZnO
   Iron        0.51 %  Fe    0.66 % FeO
   Silicon    26.56 %  Si   56.83 % SiO2
   Hydrogen    0.47 %  H     4.16 % H2O
   Oxygen     42.81 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K5.03Na6.55Mn2+12.86Mn3+1.01Fe2+0.35Mg0.18Ca0.18Zn0.09Al0.03Ti0.02Si36O88(OH)10.1�3.75(H2O)
Help on Environment: Environment: Modulated manganese phyllosilicate
Help on IMA Status: IMA Status: Approved IMA 2005 (Dana # Added)
Help on Locality: Locality: Mt. Kukisvumchorr, Kola Peninsula, Russia Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Thomas Armbruster (b. 1950; University of Berne) for his outstanding contribution to structural mineralogy and crystallography, especially to the study of Mn-rich minerals .
Help on Synonym: Synonym: IMA2005-035

Armbrusterite Image

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Comments: SEM image of a spherulite of platy crystals of armbrusterite (2 mm diameter) on cancrinite and calcite. (AmMin, v92:416).
Location: Khibiny massif, Kola Peninsula, Russia.. Scale: Spherulite Size 2 mm.
© American Mineralogist

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Comments: Translucent yellow-brown crystals of armbrusterite on small fragment of brown matrix.
Location: Kirovskii Mine, Mt. Kukisvumchorr, Khibiny, Kola Peninsula, Russia. Scale: Specimen Size 5x3x2 mm.
© John Betts - Fine Minerals

Armbrusterite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7363:1:0.573
Help on Cell Dimensions: Cell Dimensions: a = 17.3335, b = 23.539, c = 13.4895, Z = 2; beta = 115.069° V = 4,985.42 Den(Calc)= 2.54
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 12.28(1)(001 ), 3.077(0.54)(004 ), 3.26(0.18)(114 ),3.117(0.13)(203 ), 2.622(0.1)(371 ), 3.562(0.1)(113,261), 4.1(0.1)(003 ),

Physical Properties of Armbrusterite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Dark reddish brown.
Help on Density: Density: 2.78
Help on Diaphaneity: Diaphaneity: Translucent to transparent
Help on Fracture: Fracture: Brittle - Uneven - Very brittle fracture producing uneven fragments.
Help on Habit: Habit: Platy - Sheet forms (e.g. micas).
Help on Habit: Habit: Spherical - Spherical, rounded aggregates.
Help on Hardness: Hardness: 3.5 - Copper Penny
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: light brown

Optical Properties of Armbrusterite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.059 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.03 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2173,KPDmeas= 0.1986,KC= 0.2109
Ncalc = 1.54 - 1.59

Calculated Properties of Armbrusterite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.49 gm/cc
note: Specific Gravity of Armbrusterite =2.54 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEArmbrusterite = 6.92 barns/electron
U=PEArmbrusterite x relectron= 17.26 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 73.24 (Gamma Ray American Petroleum Institute Units)
Concentration of Armbrusterite per GRapi unit = 1.37 (%)

Estimated Radioactivity from Armbrusterite - barely detectable


Armbrusterite Classification

Help on  Dana Class: Dana Class: (74)Phyllosilicate Modulated Layers
  (74.01)with joined islands
  (74.01.03)Dana Group Parsettensite (K,Na,Ca)(Mn,Al)7Si8O20(OH)8•2(H2O)(?) C 2/m 2/m Armbrusterite! K5Na6MnMn14[Si9O22]4(OH)10•4H2O C 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.EG.65 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EG -Double nets with 6-membered and larger rings
09.EG.65 Armbrusterite! K5Na6MnMn14[Si9O22]4(OH)10•4H2O C 2/m 2/m

Other Armbrusterite Information

Help on References: References: NAME( AmMin, 92:416) PHYS. PROP.(AmMin, 92:416) OPTIC PROP.(AmMin, 92:416)
Help on See Also: See Also: Links to other databases for Armbrusterite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Dana No: Strunz No: 09.EG.65





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