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Bobdownsite Mineral Data

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General Bobdownsite Information

Help on Chemical  Formula: Chemical Formula: Ca9Mg(PO3F)(PO4)6
Help on Composition: Composition: Molecular Weight = 1,054.36 gm
   Sodium       0.52 %  Na    0.71 % Na2O
   Calcium     33.30 %  Ca   46.59 % CaO
   Magnesium    1.66 %  Mg    2.75 % MgO
   Aluminum     0.28 %  Al    0.53 % Al2O3
   Iron         0.90 %  Fe    0.27 % FeO /  0.98 % Fe2O3
   Phosphorus  20.56 %  P    47.12 % P2O5
   Oxygen      40.97 %  O
   Fluorine     1.80 %  F     1.80 % F
                 -   %   F    -0.76 % -O=F2    
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca8.76Na0.24Mg0.72Fe3+0.13Al0.11Fe2+0.04(PO3)F(PO4)6
Help on Environment: Environment: Whitlockite group
Help on IMA Status: IMA Status: Approved IMA 2008 (Dana # Added)
Help on Locality: Locality: Big Fish River, Yukon Territory, Canada Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Robert (Bob) Terrance Downs, Professor of Geophysics, University of Arizona, and chief advisor for the RRUFF project to collect Raman spectra of all minerals.
Help on Synonym: Synonym: IMA2008-037

Bobdownsite Image

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Comments: Colorless hexagonal tabular bobdownsite crystals in the type sample.
Location: Big Fish River, Yukon Territory, Canada. Scale: See Image.
© Rruff Database

Bobdownsite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:3.59121
Help on Cell Dimensions: Cell Dimensions: a = 10.3224, c = 37.07, Z = 6; V = 3,420.70 Den(Calc)= 3.07
Help on Crystal System: Crystal System: Trigonal - Ditrigonal Pyramidal H-M Symbol (3m) Space Group: R 3c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.181(1), 2.858(0.58), 1.714(0.32),2.986(0.19), 3.428(0.18), 2.734(0.16), 5.176(0.16), 2.586(0.13),

Physical Properties of Bobdownsite

Help on Color: Color: Colorless, White.
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Streak: Streak: white

Optical Properties of Bobdownsite

Help on Optical Data: Optical Data: NCalc= 1.6 - from Gladstone-Dale relationship (KC = 0.1965) where Ncalc=Dcalc*KC+1

Calculated Properties of Bobdownsite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.04 gm/cc
note: Specific Gravity of Bobdownsite =3.07 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0024968179
Boson Index = 0.9975031821
Help on Photoelectric: Photoelectric: PEBobdownsite = 5.41 barns/electron
U=PEBobdownsite x rElectron Density= 16.47 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Bobdownsite is Not Radioactive

Bobdownsite Classification

Help on  Dana Class: Dana Class: (38)Anhydrous Phosphates, etc
  (38.03)(A+ B++)3 (XO4)2
  (38.03.04)Whitlockite group Whitlockite Ca9(Mg,Fe)(PO4)6(PO3OH) R 3c 3m Strontiowhitlockite Sr7(Mg,Ca)3(PO4)6[PO3(OH)] R 3c 3m Merrillite-(Ca)* (Ca,[])19Mg2(PO4)14 R 3c 3m Merrillite Ca18Na2Mg2(PO4)14 R 3c 3m Merrillite-(Y)* Ca16Y2Mg2(PO4)14 R 3c 3m Ferromerrillite! Ca9NaFe(PO4)7 R 3c 3m Tuite! Ca3(PO4)2 R 3m 3m Bobdownsite! Ca9Mg(PO3F)(PO4)6 R 3c 3m
Help on  Strunz Class: Strunz Class: 08.AC.45 08 - PHOSPHATES, ARSENATES, VANADATES
  08.A - Phosphates, etc. without additional anions, without H2O
  08.AC -With medium-sized and large cations
08.AC.45 Merrillite-(Ca)* (Ca,[])19Mg2(PO4)14 R 3c 3m
08.AC.45 Merrillite Ca18Na2Mg2(PO4)14 R 3c 3m
08.AC.45 Merrillite-(Y)* Ca16Y2Mg2(PO4)14 R 3c 3m
08.AC.45 Strontiowhitlockite Sr7(Mg,Ca)3(PO4)6[PO3(OH)] R 3c 3m
08.AC.45 Whitlockite Ca9(Mg,Fe)(PO4)6(PO3OH) R 3c 3m
08.AC.45 Ferromerrillite! Ca9NaFe(PO4)7 R 3c 3m
08.AC.45 Tuite! Ca3(PO4)2 R 3m 3m
08.AC.45 Bobdownsite! Ca9Mg(PO3F)(PO4)6 R 3c 3m

Other Bobdownsite Information

Help on References: References: PHYS. PROP.(RRUFF.info)
Help on See Also: See Also: Links to other databases for Bobdownsite :
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.AC.45





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