Mineralogy Database

Gengenbachite Mineral Data

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General Gengenbachite Information

Help on Chemical  Formula: Chemical Formula: KFe3(H2PO4)2(HPO4)4•6H2O or KFe3H8(PO4)6•6H2O
Help on Composition: Composition: Molecular Weight = 892.62 gm
   Potassium    4.38 %  K     5.28 % K2O
   Iron        18.77 %  Fe   24.15 % FeO
   Phosphorus  20.82 %  P    47.71 % P2O5
   Hydrogen     2.26 %  H    20.18 % H2O
   Oxygen      53.77 %  O
              ______        ______ 
              100.00 %       97.31 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: KFe2+3H8(PO4)6•6(H2O)
Help on IMA Status: IMA Status: Proposed IMA 2006
Help on Locality: Locality: Grube Silberbr�nnle, Haigerach Valley near Gengenbach, Central Black Forest, Germany Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality.
Help on Synonym: Synonym: IMA2001-003b

Gengenbachite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:1.84649
Help on Cell Dimensions: Cell Dimensions: a = 9.12, c = 16.84, V = 1,213.00
Help on Crystal System: Crystal System: Hexagonal - Dihexagonal Pyramidal H-M Symbol (6mm) Space Group: P 63mc
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 7.16(1), 3.09(0.8), 4.57(0.7),3.23(0.6), 2.81(0.5), 3.57(0.5), 2.87(0.4), 7.89(0.4),

Optical Properties of Gengenbachite

Help on Optical Data: Optical Data:

Calculated Properties of Gengenbachite

Help on Fermion Index: Fermion Index: Fermion Index = 0.0042458883
Boson Index = 0.9957541117
Help on Photoelectric: Photoelectric: PEGengenbachite = 6.94 barns/electron
U=PEGengenbachite x relectron= . barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 63.29 (Gamma Ray American Petroleum Institute Units)
Concentration of Gengenbachite per GRapi unit = 1.58 (%)

Estimated Radioactivity from Gengenbachite - barely detectable


Gengenbachite Classification

Help on  Dana Class: Dana Class: (37)Phosphate Minerals
  (37.00)Without Dana Classification Numbers
  (37.00.00)Phosphate, Basic Hydrated Arnhemite* (K,Na)2Mg2(P2O7)•5(H2O) Unk Hex Arsenowaylandite* BiAl3(AsO4)2(OH)6 R 3m 3 2/m Auroantimonate* AuSbO3 Ortho ? Ortho Barium-zinc-alumopharmacosiderite* (Ba,K)0.5(Zn,Cu)0.5(Al,Fe)4(AsO4)3•5(H2O) I 42m 4 2m Chernovite-(Ce)* (Ce,Y)(AsO4) I 41/amd 4/m 2/m 2/m Churchite-(Dy)* (Dy,Sm,Gd,Nd)(PO4)•2(H2O) Mono Gengenbachite KFe3(H2PO4)2(HPO4)4•6H2OorKFe3H8(PO4)6•6H2O P 63mc 6mm IMA2008-063 Pb[Zn0.25,[]0.75]Fe3H(AsO4)2(OH)6 C 2/c 2/m IMA2009-005 (Y,Ca,REE)5[(Si,P)O4]3F P 63/m 6/m 2/m 2/m IMA2009-016 Cu4H(AsO4)2(OH)3•H2O P1 1 Kerstenite? PbSeO4(?) P nma 2/m 2/m 2/m Krasnoselskite* CoWO4 P 2/c 2/m Laubmannite? Fe3Fe6(PO4)4(OH)12 Unk Ortho Oxiberaunite* (Fe,Mn)Fe5(PO4)4O(OH)4•6(H2O) Mono Parwanite (Na,K)(Mg,Ca)4Al8(PO4)8(CO3)(OH)7•30H2O P 2, Pm, P 2/m, P 21, Mono Pyrocoproite* (Mg(K,Na))2P2O7 Unk Mono Pyrophosphite* K2CaP2O7 P 21/n 2/m Zinclavendulan? NaCa(Zn,Cu)5(AsO4)4Cl•4-5(H2O) Unk Ortho
Help on  Strunz Class: Strunz Class: 08.CA.65 08 - PHOSPHATES, ARSENATES, VANADATES
  08.C - Phosphates without Additional Anions, with H2O
  08.CA -With small and large/medium cations
08.CA.65 Gengenbachite KFe3(H2PO4)2(HPO4)4•6H2OorKFe3H8(PO4)6•6H2O P 63mc 6mm

Other Gengenbachite Information

Help on See Also: See Also: Links to other databases for Gengenbachite :
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 Gengenbachite Specimen Label here :


KFe3(H2PO4)2(HPO4)4•6H2O or KFe3H8(PO4)6•6H2O
Dana No: Strunz No: 08.CA.65





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