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Niobophyllite Mineral Data

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General Niobophyllite Information

Help on Chemical  Formula: Chemical Formula: K2Na(Fe++,Mn)7(Nb,Ti)2Si8O26(OH)4(F,O)
Help on Composition: Composition: Molecular Weight = 1,394.28 gm
   Potassium   5.61 %  K     6.76 % K2O
   Sodium      1.65 %  Na    2.22 % Na2O
   Titanium    0.69 %  Ti    1.15 % TiO2
   Manganese   6.90 %  Mn    8.90 % MnO
   Niobium    11.99 %  Nb   17.16 % Nb2O5
   Iron       21.03 %  Fe   27.05 % FeO
   Silicon    16.11 %  Si   34.47 % SiO2
   Hydrogen    0.29 %  H     2.58 % H2O
   Oxygen     34.71 %  O
   Fluorine    1.02 %  F     1.02 % F
                -   %   F    -0.43 % -O=F2    
             ______        ______ 
             100.00 %      100.89 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K2NaFe2+5.25Mn2+1.75Nb1.8Ti0.2Si8O26.25(OH)4F0.75
Help on Environment: Environment: Flakes in an albite-arfvedsonite paragneiss.
Help on IMA Status: IMA Status: Approved IMA 1964
Help on Locality: Locality: Ten Mile Lake, Seal Lake area, Labrador, NF, Canada. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the niobium content and foliated character common to the astrophyllite group.
Help on Name Pronunciation: Name Pronunciation: Niobophyllite + Pronunciation Say NIOBOPHYLLITE

Niobophyllite Image

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Comments: Blackish-brown resinous to silky fibrous niobophyllite coatings on quartz.
Location: Seal Lake area, Labrador, Newfoundland, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Niobophyllite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.4537:1:0.9814
Help on Cell Dimensions: Cell Dimensions: a = 5.391, b = 11.88, c = 11.66, Z = 1; alpha = 113.1°, beta = 94.5°, gamma = 103.1° V = 666.95 Den(Calc)= 3.47
Help on Crystal System: Crystal System: Triclinic Space Group: P1,P 1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.506(1), 10.52(0.9), 2.778(0.8),

Physical Properties of Niobophyllite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Brown.
Help on Density: Density: 3.42
Help on Diaphaneity: Diaphaneity: Translucent to Opaque
Help on Habit: Habit: Flakes - Flat, thin crystals or aggregates.
Help on Habit: Habit: Foliated - Two dimensional platy forms.
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luster: Luster: Vitreous - Adamantine

Optical Properties of Niobophyllite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2136,KPDmeas= 0.2199,KC= 0.2173
Ncalc = 1.74 - 1.76
Help on Optical Data: Optical Data: Biaxial (-), a=1.724, b=1.76, g=1.772, bire=0.0480, 2V(Calc)=58, 2V(Meas)=60.

Calculated Properties of Niobophyllite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.30 gm/cc
note: Specific Gravity of Niobophyllite =3.42 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PENiobophyllite = 27.04 barns/electron
U=PENiobophyllite x relectron= 89.17 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 78.01 (Gamma Ray American Petroleum Institute Units)
Concentration of Niobophyllite per GRapi unit = 1.28 (%)

Estimated Radioactivity from Niobophyllite - barely detectable


Niobophyllite Classification

Help on  Dana Class: Dana Class: (69)Inosilicate Chains with Side Branches or Loops
  (69.01)with (P=2, and N=4, 2 branches)
  (69.01.01)Astrophyllite group Astrophyllite K2Na(Fe,Mn)7Ti2Si8O26(OH)4 P1 1 Kupletskite K2Na(Mn,Fe)7(Ti,Nb)2Si8O26(OH)4F C 2/c 2/m Kupletskite-(Cs) (Cs,K)2Na(Mn,Fe,Li)7(Ti,Nb)2Si8O26(OH)4F P1 1 Niobophyllite K2Na(Fe,Mn)7(Nb,Ti)2Si8O26(OH)4(F,O) P1,P 1 Tri Zircophyllite K2(Na,Ca)(Mn,Fe)7(Zr,Nb)2Si8O26(OH)4F P1 1 Hydroastrophyllite (H3O,K)2Ca(Fe,Mn)5-6Ti2Si8O26(OH)4F P1 1 Magnesioastrophyllite K2Na[Na(Fe,Fe,Mn)Mg2]Ti2Si8O26(OH)4F A2/m 2/m Niobokupletskite! K2Na(Mn,Zn,Fe)7(Nb,Zr,Ti)2Si8O26(OH)4(O,F) P1 1 Nalivkinite! Li2NaFe7Ti2Si8O24(OH)4F P1 1
Help on  Strunz Class: Strunz Class: 09.DC.05 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DC -Inosilicates with branched 2-periodic single chains Si2O6 + 2SiO3 � Si4O12
09.DC.05 Astrophyllite K2Na(Fe,Mn)7Ti2Si8O26(OH)4 P1 1
09.DC.05 Kupletskite-(Cs) (Cs,K)2Na(Mn,Fe,Li)7(Ti,Nb)2Si8O26(OH)4F P1 1
09.DC.05 Kupletskite K2Na(Mn,Fe)7(Ti,Nb)2Si8O26(OH)4F C 2/c 2/m
09.DC.05 Magnesioastrophyllite K2Na[Na(Fe,Fe,Mn)Mg2]Ti2Si8O26(OH)4F A2/m 2/m
09.DC.05 Hydroastrophyllite (H3O,K)2Ca(Fe,Mn)5-6Ti2Si8O26(OH)4F P1 1
09.DC.05 Niobophyllite K2Na(Fe,Mn)7(Nb,Ti)2Si8O26(OH)4(F,O) P1,P 1 Tri
09.DC.05 Nalivkinite! Li2NaFe7Ti2Si8O24(OH)4F P1 1
09.DC.05 Zircophyllite K2(Na,Ca)(Mn,Fe)7(Zr,Nb)2Si8O26(OH)4F P1 1
09.DC.05 Niobokupletskite! K2Na(Mn,Zn,Fe)7(Nb,Zr,Ti)2Si8O26(OH)4(O,F) P1 1

Other Niobophyllite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Niobophyllite :
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

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Dana No: Strunz No: 09.DC.05





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