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Vajdakite Mineral Data

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General Vajdakite Information

Help on Chemical  Formula: Chemical Formula: [(MoO2)2(H2O)2As2O5]•(H2O)
Help on Composition: Composition: Molecular Weight = 535.57 gm
   Molybdenum  34.04 %  Mo   51.06 % MoO3
   Arsenic     27.98 %  As   36.94 % As2O3
   Hydrogen     1.24 %  H    11.10 % H2O
   Oxygen      36.74 %  O
              ______        ______ 
              100.00 %       99.10 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mo1.9As2O9•3.3(H2O)
Help on Environment: Environment: On fractures in proximity to an ore vein. Formed by concentrated sulfuric acid in the presence of As2O3.
Help on IMA Status: IMA Status: Approved IMA 1999 (Dana # Added)
Help on Locality: Locality: Jachymov, NW Bohemia, Czech Republic. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Josef Vajdak (1930-), for his significant contribution in the study of minerals in the Jachymov ore district.
Help on Synonym: Synonym: IMA1998-031

Vajdakite Image

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Comments: Scanning electron microscope photograph of aggregate of acicular vajdakite crystals (AmMin, 87:984).
Location: Jáchymov, NW Bohemia, Czech Republic. Scale: 300x magnification.
© American Mineralogist

Vajdakite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.5832:1:1.0106
Help on Cell Dimensions: Cell Dimensions: a = 7.0515, b = 12.0908, c = 12.219, Z = 4; beta = 101.268° V = 1,021.69 Den(Calc)= 3.48
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 6.046(1)(020), 3.324(0.59)(023), 6.915(0.26)(100),2.264(0.19)(310), 3.457(0.16)(200), 2.624(0.15)(230), 2.593(0.12), 3.819(0.1)(031),

Physical Properties of Vajdakite

Help on Cleavage: Cleavage: {100} Perfect, {010} Good
Help on Color: Color: Green, Greenish gray.
Help on Density: Density: 3.5
Help on Diaphaneity: Diaphaneity: Translucent
Help on Habit: Habit: Acicular - Occurs as needle-like crystals.
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: light grayish green

Optical Properties of Vajdakite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.001 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.004 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2466,KPDmeas= 0.2452,KC= 0.2456
Ncalc = 1.85 - 1.86
Help on Optical Data: Optical Data: Biaxial (+), a=1.757, b=1.778, g=2.04, bire=0.2830

Calculated Properties of Vajdakite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.28 gm/cc
note: Specific Gravity of Vajdakite =3.50 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.08
Boson Index = 0.92
Help on Photoelectric: Photoelectric: PEVajdakite = 74.94 barns/electron
U=PEVajdakite x rElectron Density= 245.66 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Vajdakite is Not Radioactive

Vajdakite Classification

Help on  Dana Class: Dana Class: (49)Basic and Hydrated Molybdates and Tungstates
  (49.04)(Compound Anions)
  (49.04.08)Dana Group Vajdakite! [(MoO2)2(H2O)2As2O5]•(H2O) P 21/c 2/m
Help on  Strunz Class: Strunz Class: 04.JC.20 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.J - Arsenites, Antimonites, Bismuthites, Sulfites,
  04.JC -Arsenites, antimonites, bismuthites; without additional anions, with H2O
04.JC.20 Vajdakite! [(MoO2)2(H2O)2As2O5]•(H2O) P 21/c 2/m

Other Vajdakite Information

Help on References: References: NAME( AmMin, Vol 87, p 983) PHYS. PROP.(AmMin, Vol 87, p 983) OPTIC PROP.(AmMin, Vol 87, p 983)
Help on See Also: See Also: Links to other databases for Vajdakite :
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: 04.JC.20





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