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Rankachite Mineral Data

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General Rankachite Information

Help on Chemical  Formula: Chemical Formula: CaFe++V+++++4W++++++8O36•12(H2O)
Help on Composition: Composition: Molecular Weight = 2,562.65 gm
   Calcium    1.56 %  Ca    2.19 % CaO
   Vanadium   7.95 %  V    14.19 % V2O5
   Iron       2.18 %  Fe    2.80 % FeO
   Hydrogen   0.94 %  H     8.44 % H2O
   Tungsten  57.39 %  W    72.38 % WO3
   Oxygen    29.97 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaFe2+V5+4W8O36•12(H2O)
Help on Environment: Environment: Secondary mineral in a mine.
Help on IMA Status: IMA Status: Approved IMA 1984
Help on Locality: Locality: Clara Mine, Wofach, Rankach Valley, Schwarzwald, Balden-Wurttenberg, Germany. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality.
Help on Name Pronunciation: Name Pronunciation: Rankachite + Pronunciation Say RANKACHITE

Rankachite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.1944:1:0.1297
Help on Cell Dimensions: Cell Dimensions: a = 8.17, b = 42.02, c = 5.45, Z = 2; V = 1,871.00 Den(Calc)= 4.55
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pmmn
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 10.64(1), 5.44(0.7), 4.57(0.6),

Physical Properties of Rankachite

Help on Cleavage: Cleavage: {100} Perfect, {010} Perfect
Help on Color: Color: Brownish yellow, Dark brown.
Help on Density: Density: 4.5
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Habit: Habit: Encrustations - Forms crust-like aggregates on matrix.
Help on Habit: Habit: Rosette - Bundled tabular aggregates resembling rose flower petals.
Help on Hardness: Hardness: 2.5 - Finger Nail
Help on Luster: Luster: Adamantine - Greasy
Help on Streak: Streak: light brown

Optical Properties of Rankachite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.063 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.073 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1952,KPDmeas= 0.1974,KC= 0.2106
Ncalc = 1.95 - 1.96
Help on Optical Data: Optical Data: Biaxial (-), a=1.77, b=1.925, g=1.97, bire=0.2000, 2V(Calc)=52, 2V(Meas)=58. Dispersion r << v.
Help on Pleochroism (x): Pleochroism (x): yellow brown.
Help on Pleochroism (y): Pleochroism (y): deep reddish brown.
Help on Pleochroism (z): Pleochroism (z): deep reddish brown.

Calculated Properties of Rankachite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.00 gm/cc
note: Specific Gravity of Rankachite =4.50 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.08
Boson Index = 0.92
Help on Photoelectric: Photoelectric: PERankachite = 699.88 barns/electron
U=PERankachite x rElectron Density=2,797.17 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Rankachite is Not Radioactive

Rankachite Classification

Help on  Dana Class: Dana Class: (49)Basic and Hydrated Molybdates and Tungstates
  (49.03)(Hydrated, containing Hydroxyl or Halogen)
  (49.03.06)Dana Group Rankachite CaFeV4W8O36•12(H2O) Pmmn 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 07.GB.25 07 - SULFATES (SELENATES, TELLURATES)
  07.G - Molybdates, Wolframates and Niobates
  07.GB -With additional anions and/or H2O
07.GB.25 Rankachite CaFeV4W8O36•12(H2O) Pmmn 2/m 2/m 2/m

Other Rankachite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Rankachite :
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: 07.GB.25





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