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Grischunite Mineral Data

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General Grischunite Information

Help on Chemical  Formula: Chemical Formula: NaCa2Mn++5Fe+++(AsO4)6•2(H2O)
Help on Composition: Composition: Molecular Weight = 1,303.23 gm
   Sodium      1.76 %  Na    2.38 % Na2O
   Calcium     6.15 %  Ca    8.61 % CaO
   Manganese  21.08 %  Mn   27.22 % MnO
   Iron        4.29 %  Fe    6.13 % Fe2O3
   Arsenic    34.49 %  As   52.91 % As2O5
   Hydrogen    0.31 %  H     2.76 % H2O
   Oxygen     31.92 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: NaCa2Mn2+5Fe3+(AsO4)6•2(H2O)
Help on Environment: Environment: Alteration product of sarkinite in a manganese deposit.
Help on IMA Status: IMA Status: Approved IMA 1984
Help on Locality: Locality: Falotta mine, Oberhalbstein, Graub�unden, Switzerland. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named from the former Romansch name Grischun for Graubunden Canton.
Help on Name Pronunciation: Name Pronunciation: Grischunite + Pronunciation Say GRISCHUNITE
Help on Synonym: Synonym: ICSD 63431
  PDF 38-387

Grischunite Image

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Comments: Red-brown prismatic grischunite crystals on matrix.
Location: Falotta, Tinzen, Oberhalbstein, Graubünden, Switzerland. Scale: Specimen Size 1.5x2 cm.
© Diederik Visser

Grischunite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9531:1:0.8932
Help on Cell Dimensions: Cell Dimensions: a = 12.855, b = 13.487, c = 12.047, Z = 4; V = 2,088.65 Den(Calc)= 4.14
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pcab
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.839(1), 3.15(0.9), 3.015(0.8),

Physical Properties of Grischunite

Help on Cleavage: Cleavage: {???} Perfect
Help on Color: Color: Dark reddish brown.
Help on Density: Density: 3.8
Help on Hardness: Hardness: 5 - Apatite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: brown

Optical Properties of Grischunite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.086 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.004 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1899,KPDmeas= 0.2069,KC= 0.1906
Ncalc = 1.72 - 1.79
Help on Optical Data: Optical Data: Biaxial (+), a=1.784, b=1.785, g=1.79, bire=0.0060, 2V(Calc)=50, 2V(Meas)=40-50.

Calculated Properties of Grischunite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.89 gm/cc
note: Specific Gravity of Grischunite =4.14 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0011451898
Boson Index = 0.9988548102
Help on Photoelectric: Photoelectric: PEGrischunite = 31.47 barns/electron
U=PEGrischunite x rElectron Density= 122.38 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Grischunite is Not Radioactive

Grischunite Classification

Help on  Dana Class: Dana Class: (40)Hydrated Phosphates, etc
  (40.02)where A++ (B++)2 (XO4) � x(H2O)
  (40.02.11)Dana Group Grischunite NaCa2Mn5Fe(AsO4)6•2(H2O) Pcab 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 08.CF.05 08 - PHOSPHATES, ARSENATES, VANADATES
  08.C - Phosphates without Additional Anions, with H2O
  08.CF -With large and medium-sized cations, RO4:H2O > 1:1
08.CF.05 Grischunite NaCa2Mn5Fe(AsO4)6•2(H2O) Pcab 2/m 2/m 2/m
08.CF.05 Wicksite NaCa2(Fe,Mn)4MgFe(PO4)6•2(H2O) P bca 2/m 2/m 2/m
08.CF.05 Bederite! ([],Na)Ca2(Mn,Mg,Fe)2(Fe,Mg,Al)2Mn2(PO4)6•2(H2O) Pcab 2/m 2/m 2/m
08.CF.05 Tassieite! (Na,[])Ca2(Mg,Fe,Fe)2(Fe,Mg)2(Fe,Mg)2(PO4)6(H2O)2 P bca 2/m 2/m 2/m

Other Grischunite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Grischunite :
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: 08.CF.05





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