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Johnsomervilleite Mineral Data

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General Johnsomervilleite Information

Help on Chemical  Formula: Chemical Formula: Na2Ca(Mg,Fe++,Mn)7(PO4)6
Help on Composition: Composition: Molecular Weight = 955.37 gm
   Sodium       3.37 %  Na    4.54 % Na2O
   Calcium      4.61 %  Ca    6.46 % CaO
   Magnesium    7.89 %  Mg   13.08 % MgO
   Manganese    4.03 %  Mn    5.20 % MnO
   Iron        20.46 %  Fe   26.32 % FeO
   Phosphorus  19.45 %  P    44.57 % P2O5
   Oxygen      40.19 %  O
              ______        ______ 
              100.00 %      100.17 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na1.4Ca1.1Fe2+3.5Mg3.1Mn2+0.7(PO4)6
Help on Environment: Environment: Accessory mineral in podiform metamorphic segregations in kyanite-sillimanite-grade gneiss.
Help on IMA Status: IMA Status: Approved IMA 1980
Help on Locality: Locality: Glen Cosaidh, Loch Quoich,, Inverness-shire, Scotland. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for John M. Somerville (1908-1978), who collected the first specimen.
Help on Name Pronunciation: Name Pronunciation: Johnsomervilleite + Pronunciation Say JOHNSOMERVILLEITE

Johnsomervilleite Image

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Comments: Dark brownish johnsomervilleite.
Location: Sapucaia Mine, Conselheiro Pena district, Galiléia, Governador Valadares, Rio Doce, Minas Gerais, Southeast Region, Brazil. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Johnsomervilleite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:2.84999
Help on Cell Dimensions: Cell Dimensions: a = 15, c = 42.75, Z = 18; V = 8,330.08 Den(Calc)= 3.43
Help on Crystal System: Crystal System: Trigonal - Rhombohedral H-M Symbol ( 3) Space Group: R 3
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.764(1), 3.55(0.7), 3.7(0.7),

Physical Properties of Johnsomervilleite

Help on Cleavage: Cleavage: {0001} Perfect
Help on Color: Color: Dark brown, Blackish gray.
Help on Density: Density: 3.35
Help on Diaphaneity: Diaphaneity: Transparent to Translucent
Help on Fracture: Fracture: Brittle - Splintery - Brittle fracture leaving splintery fragments.
Help on Habit: Habit: Colloform - Forming from a gel or colloidal mass.
Help on Habit: Habit: Dendritic - Branching "tree-like" growths of great complexity (e.g. pyrolusite).
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Hardness: Hardness: 4.5 - Between Fluorite and Apatite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: light brown

Optical Properties of Johnsomervilleite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.031 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.007 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.191,KPDmeas= 0.1955,KC= 0.1896
Ncalc = 1.64 - 1.65
Help on Optical Data: Optical Data: Uniaxial (+/-), a=1.655, b=1.655, bire=0.0000.

Calculated Properties of Johnsomervilleite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.34 gm/cc
note: Specific Gravity of Johnsomervilleite =3.43 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEJohnsomervilleite = 8.87 barns/electron
U=PEJohnsomervilleite x rElectron Density= 29.62 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Johnsomervilleite is Not Radioactive

Johnsomervilleite Classification

Help on  Dana Class: Dana Class: (38)Anhydrous Phosphates, etc
  (38.02)(A+ B++)5 (XO4)3
  (38.02.05)Fillowite Group Fillowite Na2Ca(Mn,Fe)7(PO4)6 R 3 3 Johnsomervilleite Na2Ca(Mg,Fe,Mn)7(PO4)6 R 3 3 Chladniite Na2Ca(Mg,Fe)7(PO4)6 R 3 3 Galileiite! NaFe4(PO4)3 R 3 3 Xenophyllite! Na4Fe7(PO4)6 P1 or P1 Tri Stornesite-(Y)! (Y,Ca)[]2Na6(Ca,Na)8(Mg,Fe)43(PO4)36 R 3 3
Help on  Strunz Class: Strunz Class: 08.AC.50 08 - PHOSPHATES, ARSENATES, VANADATES
  08.A - Phosphates, etc. without additional anions, without H2O
  08.AC -With medium-sized and large cations
08.AC.50 Fillowite Na2Ca(Mn,Fe)7(PO4)6 R 3 3
08.AC.50 Chladniite Na2Ca(Mg,Fe)7(PO4)6 R 3 3
08.AC.50 Johnsomervilleite Na2Ca(Mg,Fe,Mn)7(PO4)6 R 3 3
08.AC.50 Galileiite! NaFe4(PO4)3 R 3 3
08.AC.50 Stornesite-(Y)! (Y,Ca)[]2Na6(Ca,Na)8(Mg,Fe)43(PO4)36 R 3 3
08.AC.50 Xenophyllite! Na4Fe7(PO4)6 P1 or P1 Tri

Other Johnsomervilleite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Johnsomervilleite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Dana No: Strunz No: 08.AC.50





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