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Jahnsite-(CaMnMg) Mineral Data

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General Jahnsite-(CaMnMg) Information

Help on Chemical  Formula: Chemical Formula: CaMnMg2Fe+++2(PO4)4(OH)2•8(H2O)
Help on Composition: Composition: Molecular Weight = 813.34 gm
   Calcium      4.93 %  Ca    6.89 % CaO
   Magnesium    5.98 %  Mg    9.91 % MgO
   Manganese    6.75 %  Mn    8.72 % MnO
   Iron        13.73 %  Fe   19.63 % Fe2O3
   Phosphorus  15.23 %  P    34.90 % P2O5
   Hydrogen     2.23 %  H    19.93 % H2O
   Oxygen      51.15 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaMn2+Mg2Fe3+2(PO4)4(OH)2•8(H2O)
Help on IMA Status: IMA Status: Approved IMA 1974
Help on Locality: Locality: Tip Top pegmatite, Custer, 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-(CaMnMg) Say JAHNSITE-(CAMNMG)
Help on Synonym: Synonym: Jahnsite
 

Jahnsite-(CaMnMg) Image

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  Jahnsite-(CaMnMg)

Comments: Brown, striated, transparent crystals of jahnsite-(CaMnMg) on matrix.
Location: Tip Top mine, Custer, Custer County, South Dakota, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Jahnsite-(CaMnMg) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =2.0924:1:1.3907
Help on Cell Dimensions: Cell Dimensions: a = 14.94, b = 7.14, c = 9.93, Z = 2; beta = 110.68° V = 991.00 Den(Calc)= 2.73
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): 9.27(1), 2.825(0.8), 4.91(0.6),
 

Physical Properties of Jahnsite-(CaMnMg)

Help on Cleavage: Cleavage: {001} Good
Help on Color: Color: Brown, Purplish brown, Yellow, Yellow orange, Greenish yellow.
Help on Density: Density: 2.706 - 2.718, Average = 2.71
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Hardness: Hardness: 4 - Fluorite
Help on Luster: Luster: Vitreous - Adamantine
Help on Streak: Streak: white
 

Optical Properties of Jahnsite-(CaMnMg)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.013 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.019 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2403,KPDmeas= 0.2419,KC= 0.245
Ncalc = 1.66 - 1.67
Help on Optical Data: Optical Data: Biaxial (+), a=1.64, b=1.658, g=1.67, bire=0.0300
Help on Pleochroism (x): Pleochroism (x): pale purple.
Help on Pleochroism (y): Pleochroism (y): deep purplish brown.
Help on Pleochroism (z): Pleochroism (z): greenish yellow.
 

Calculated Properties of Jahnsite-(CaMnMg)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.71 gm/cc
note: Specific Gravity of Jahnsite-(CaMnMg) =2.71 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0092032727
Boson Index = 0.9907967273
Help on Photoelectric: Photoelectric: PEJahnsite-(CaMnMg) = 7.19 barns/electron
U=PEJahnsite-(CaMnMg) x rElectron Density= 19.50 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Jahnsite-(CaMnMg) is Not Radioactive
 

Jahnsite-(CaMnMg) Classification

Help on  Dana Class: Dana Class: 42.11.02.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.11)where (AB)4 (XO4)3 Zq � x(H2O)
  (42.11.02)Jahnsite Group
 
42.11.02.01 Jahnsite-(CaMnMg) CaMnMg2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
42.11.02.02 Jahnsite-(CaMnFe) CaMnFe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
42.11.02.03 Jahnsite-(CaMnMn) CaMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m
 
42.11.02.04 Jahnsite-(MnMnMn)* MnMnMn2Fe2(PO4)4(OH)2•8(H2O) 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-(CaMnMg) Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Jahnsite-(CaMnMg) :
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
11 - WWW-MINCRYST

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Print or Cut-and-Paste your Jahnsite-(CaMnMg) Specimen Label here :

Jahnsite-(CaMnMg)

CaMnMg2Fe+++2(PO4)4(OH)2•8(H2O)
Dana No: 42.11.02.01 Strunz No: 08.DH.15
Locality:

 

Notes:

 

 
   
 


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