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Guimaraesite Mineral Data

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General Guimaraesite Information

Help on Chemical  Formula: Chemical Formula: Ca2(Zn,Mg,Fe)5Be4(PO4)6(OH)4•6H2O
Help on Composition: Composition: Molecular Weight = 1,107.66 gm
   Calcium      7.24 %  Ca   10.13 % CaO
   Magnesium    3.84 %  Mg    6.37 % MgO
   Beryllium    3.25 %  Be    9.03 % BeO
   Zinc        13.28 %  Zn   16.53 % ZnO
   Iron         5.04 %  Fe    6.49 % FeO
   Phosphorus  16.78 %  P    38.44 % P2O5
   Hydrogen     1.46 %  H    13.01 % H2O
   Oxygen      49.11 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca2Zn2.25Mg1.75Fe2+Be4(PO4)6(OH)4•6(H2O)
Help on Environment: Environment: Roscherite group. Zinc analog of zanazziite.
Help on IMA Status: IMA Status: Proposed IMA 2006
Help on Locality: Locality: Granite pegmatite near the Piau� river, Itinga county, Minas Gerais, Brazil Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Commission on New Minerals, Nomenclature and Classification (CNMNC)
Help on Synonym: Synonym: IMA2006-028

Guimaraesite Image

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Comments: Brown guimaraesite spheres and crystal aggregates..
Location: Piaui district, Itinga, Minas Gerais, Brazil. Scale: Specimen size 2 mm.
© Diederik Visser

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Comments: Botryoidal guimaraesite on eosphorite.
Location: Piaul District, Itinga, Minas Gerais, Brazil. Scale: Specimen size 1.1 x 0.9 x 0.8 cm.
© Rob Lavinsky

Guimaraesite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.3496:1:0.5599
Help on Cell Dimensions: Cell Dimensions: a = 15.98, b = 11.84, c = 6.63, Z = 2; beta = 95.15° V = 1,249.35 Den(Calc)= 2.94
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 5.98(1), 3.152(0.9), 9.48(0.9),4.82(0.8), 2.708(0.8), 2.961(0.7), 3.052(0.7), 2.841(0.7),

Physical Properties of Guimaraesite

Help on Color: Color: Brown.
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Luster: Luster: Vitreous (Glassy)

Optical Properties of Guimaraesite

Help on Optical Data: Optical Data: NCalc= 1.61 - from Gladstone-Dale relationship (KC = 0.2086) where Ncalc=Dcalc*KC+1

Calculated Properties of Guimaraesite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.91 gm/cc
note: Specific Gravity of Guimaraesite =2.94 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.04
Boson Index = 0.96
Help on Photoelectric: Photoelectric: PEGuimaraesite = 9.74 barns/electron
U=PEGuimaraesite x rElectron Density= 28.37 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Guimaraesite is Not Radioactive

Guimaraesite Classification

Help on  Dana Class: Dana Class: (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.07)where (AB)5 (XO4)3 Zq � x(H2O)
  (42.07.07)Roscherite group Roscherite Ca(Mn,Fe)5Be4(PO4)6(OH)4•6(H2O) C1 1 Zanazziite Ca2(Mg,Fe)(Mg,Fe,Al,Mn,Fe)4Be4(PO4)6(OH)4•6(H2O) C 2/c 2/m Greifensteinite! Ca2Be4(Fe,Mn)5(PO4)6(OH)4•6(H2O) C 2/c 2/m Atencioite! Ca2Fe[]Mg2Fe2Be4(PO4)6(OH)4•6H2O P1 1 Guimaraesite Ca2(Zn,Mg,Fe)5Be4(PO4)6(OH)4•6H2O C 2/c 2/m Footemineite! Ca2MnMn2Mn2Be4(PO4)6(OH)4•6H2O P1 1 Ruifrancoite! Ca2([],Mn)2(Fe,Mn,Mg)4Be4(PO4)6(OH)4•6H2O C 2/c 2/m
Help on  Strunz Class: Strunz Class: 08.DA.10 08 - PHOSPHATES, ARSENATES, VANADATES
  08.D - Phosphates, etc
  08.DA -With small (and occasionally larger) cations
08.DA.10 Roscherite Ca(Mn,Fe)5Be4(PO4)6(OH)4•6(H2O) C1 1
08.DA.10 Zanazziite Ca2(Mg,Fe)(Mg,Fe,Al,Mn,Fe)4Be4(PO4)6(OH)4•6(H2O) C 2/c 2/m
08.DA.10 Footemineite! Ca2MnMn2Mn2Be4(PO4)6(OH)4•6H2O P1 1
08.DA.10 Atencioite! Ca2Fe[]Mg2Fe2Be4(PO4)6(OH)4•6H2O P1 1
08.DA.10 Greifensteinite! Ca2Be4(Fe,Mn)5(PO4)6(OH)4•6(H2O) C 2/c 2/m
08.DA.10 Ruifrancoite! Ca2([],Mn)2(Fe,Mn,Mg)4Be4(PO4)6(OH)4•6H2O C 2/c 2/m
08.DA.10 Guimaraesite Ca2(Zn,Mg,Fe)5Be4(PO4)6(OH)4•6H2O C 2/c 2/m

Other Guimaraesite Information

Help on See Also: See Also: Links to other databases for Guimaraesite :
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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Dana No: Strunz No: 08.DA.10





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