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Jahnsite-(NaFeMg) Mineral Data

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General Jahnsite-(NaFeMg) Information

Help on Chemical  Formula: Chemical Formula: NaFe+++Mg2Fe+++2(PO4)4(OH)2•8H2O
Help on Composition: Composition: Molecular Weight = 780.46 gm
   Sodium       2.12 %  Na    2.86 % Na2O
   Calcium      0.26 %  Ca    0.36 % CaO
   Magnesium    6.26 %  Mg   10.38 % MgO
   Manganese    0.28 %  Mn    0.36 % MnO
   Iron        19.46 %  Fe   27.83 % Fe2O3
   Phosphorus  15.87 %  P    36.37 % P2O5
   Hydrogen     2.44 %  H    21.84 % H2O
   Oxygen      53.30 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na0.72Ca0.05Mn2+0.04Fe3+0.72Mg0.01Mg2Fe3+24(P)4(O3.77)4(OH)0.23(OH)2�8(H2O)
Help on Environment: Environment: Found in a single football-sized rock, consisting mainly of heterosite and presumed to be a fragment of highly altered and oxidized triphylite. Whiteite-jahnsite group.
Help on IMA Status: IMA Status: Approved IMA 2007 (Dana # Added)
Help on Locality: Locality: Tip Top mine, Custer County, South Dakota, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Richard H. Jahns (1915-1983), mineralogist and pegmatite expert, Stanford University, Palo Alto, California, USA.
Help on Name Pronunciation: Name Pronunciation: Jahnsite-(NaFeMg) Say JAHNSITE-(NAFEMG)
Help on Synonym: Synonym: IMA2007-016
 

Jahnsite-(NaFeMg) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =2.1121:1:1.3766
Help on Cell Dimensions: Cell Dimensions: a = 15.0811, b = 7.1403, c = 9.8299, Z = 2; beta = 110.445° V = 991.84 Den(Calc)= 2.61
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2/a
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 9.218(1), 2.819(0.7), 2.593(0.25),2.973(0.25), 3.537(0.25), 4.884(0.25), 1.933(0.2), 2.854(0.2),
 

Physical Properties of Jahnsite-(NaFeMg)

Help on Color: Color: Yellow.
Help on Density: Density: 2.58
Help on Diaphaneity: Diaphaneity: Transparent
Help on Fracture: Fracture: Brittle - Splintery - Brittle fracture leaving splintery fragments.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Habit: Habit: Striated - Parallel lines on crystal surface or cleavage face.
Help on Hardness: Hardness: 4 - Fluorite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white
 

Optical Properties of Jahnsite-(NaFeMg)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.005 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2519,KPDmeas= 0.2548,KC= 0.2561
Ncalc = 1.66 - 1.67
Help on Optical Data: Optical Data: Biaxial (-), a=1.632, b=1.669, g=1.671, bire=0.0390, 2V(Calc)=24, 2V(Meas)=25. Dispersion very strong, r > v.
 

Calculated Properties of Jahnsite-(NaFeMg)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.59 gm/cc
note: Specific Gravity of Jahnsite-(NaFeMg) =2.58 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEJahnsite-(NaFeMg) = 6.74 barns/electron
U=PEJahnsite-(NaFeMg) x rElectron Density= 17.46 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Jahnsite-(NaFeMg) is Not Radioactive
 

Jahnsite-(NaFeMg) Classification

Help on  Dana Class: Dana Class: 42.11.03.06 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.11)where (AB)4 (XO4)3 Zq � x(H2O)
  (42.11.03)Whiteite Group
 
42.11.03.01 Whiteite-(CaFeMg) Ca(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 21/a 2/m
 
42.11.03.02 Whiteite-(MnFeMg) (Mn,Ca)(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
42.11.03.03 Whiteite-(CaMnMg) CaMnMg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
42.11.03.04 Rittmannite MnMnFeAl2(OH)2(PO4)4•8(H2O) P 2/a 2/m
 
42.11.03.05 Jahnsite-(CaFeFe)! (Ca,Mn)(Fe,Mn)Fe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
42.11.03.06 Jahnsite-(NaFeMg)! NaFeMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m
 
42.11.03.07 Jahnsite-(CaMgMg)! CaMgMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m
 
42.11.03.08 Jahnsite-(NaMnMg)! NaMnMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m
Help on  Strunz Class: Strunz Class: 08.DH.15 08 - PHOSPHATES, ARSENATES, VANADATES
  08.D - Phosphates, etc
  08.DH -With large and medium-sized cations, (OH, etc.):RO4 < 1:1
 
08.DH.15 Keckite Ca(Mn,Zn)2Fe3(PO4)4(OH)3•2(H2O) P 21/a 2/m
 
08.DH.15 Jahnsite-(CaMnFe) CaMnFe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Jahnsite-(CaMnMg) CaMnMg2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Jahnsite-(CaMnMn) CaMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Jahnsite-(MnMnMn)* MnMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Kaluginite* (Mn,Ca)MgFe(PO4)2(OH)•4(H2O) C cca 2/m 2/m 2/m
 
08.DH.15 Rittmannite MnMnFeAl2(OH)2(PO4)4•8(H2O) P 2/a 2/m
 
08.DH.15 Whiteite-(MnFeMg) (Mn,Ca)(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Whiteite-(CaFeMg) Ca(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 21/a 2/m
 
08.DH.15 Whiteite-(CaMnMg) CaMnMg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Jahnsite-(CaFeFe)! (Ca,Mn)(Fe,Mn)Fe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
08.DH.15 Jahnsite-(NaFeMg)! NaFeMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m
 
08.DH.15 Jahnsite-(CaMgMg)! CaMgMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m
 
08.DH.15 Jahnsite-(NaMnMg)! NaMnMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m
 

Other Jahnsite-(NaFeMg) Information

Help on References: References: NAME( AmMin, v93:940) PHYS. PROP.(AmMin, v93:940) OPTIC PROP.(AmMin, v93:940)
Help on See Also: See Also: Links to other databases for Jahnsite-(NaFeMg) :
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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Print or Cut-and-Paste your Jahnsite-(NaFeMg) Specimen Label here :

Jahnsite-(NaFeMg)

NaFe+++Mg2Fe+++2(PO4)4(OH)2•8H2O
Dana No: 42.11.03.06 Strunz No: 08.DH.15
Locality:

 

Notes:

 

 
   
 


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