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Jahnsite-(CaMgMg) Mineral Data

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General Jahnsite-(CaMgMg) Information

Help on Chemical  Formula: Chemical Formula: CaMgMg2Fe+++2(PO4)4(OH)2•8H2O
Help on Composition: Composition: Molecular Weight = 782.71 gm
   Calcium      5.12 %  Ca    7.16 % CaO
   Magnesium    9.32 %  Mg   15.45 % MgO
   Iron        14.27 %  Fe   20.40 % Fe2O3
   Phosphorus  15.83 %  P    36.27 % P2O5
   Hydrogen     2.32 %  H    20.71 % H2O
   Oxygen      53.15 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaMg3Fe3+2(PO4)4(OH)2•8(H2O)
Help on Environment: Environment: Zoned tip on Jahnsite-(NaFeMg). Whiteite-jahnsite group.
Help on IMA Status: IMA Status: Not Submitted IMA (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-(CaMgMg) Say JAHNSITE-(CAMGMG)
Help on Synonym: Synonym: IMA2007-016
 

Jahnsite-(CaMgMg) Crystallography

Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2/a
 

Physical Properties of Jahnsite-(CaMgMg)

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-(CaMgMg)

Help on Optical Data: Optical Data: Biaxial (-)
  NCalc= 1.64 - from Gladstone-Dale relationship (KC = 0.247) where Ncalc=Dmeas*KC+1
 

Calculated Properties of Jahnsite-(CaMgMg)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.60 gm/cc
note: Specific Gravity of Jahnsite-(CaMgMg) =2.58 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEJahnsite-(CaMgMg) = 5.77 barns/electron
U=PEJahnsite-(CaMgMg) x rElectron Density= 14.99 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Jahnsite-(CaMgMg) is Not Radioactive
 

Jahnsite-(CaMgMg) Classification

Help on  Dana Class: Dana Class: 42.11.03.07 (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-(CaMgMg) 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-(CaMgMg) :
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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Jahnsite-(CaMgMg)

CaMgMg2Fe+++2(PO4)4(OH)2•8H2O
Dana No: 42.11.03.07 Strunz No: 08.DH.15
Locality:

 

Notes:

 

 
   
 


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