General Vajdakite Information Chemical Formula: |
[(MoO2)2(H2O)2As2O5]•(H2O) |
Composition: |
Molecular Weight = 535.57 gm |
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Molybdenum 34.04 % Mo 51.06 % MoO3 |
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Arsenic 27.98 % As 36.94 % As2O3 |
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Hydrogen 1.24 % H 11.10 % H2O |
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Oxygen 36.74 % O |
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______ ______ |
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100.00 % 99.10 % = TOTAL OXIDE |
Empirical Formula: |
Mo1.9As2O9•3.3(H2O) |
Environment: |
On fractures in proximity to an ore vein. Formed by concentrated sulfuric acid in the presence of As2O3. |
IMA Status: |
Approved IMA 1999 (Dana # Added) |
Locality: |
Jachymov, NW Bohemia, Czech Republic. Link to MinDat.org Location Data. |
Name Origin: |
Named for Josef Vajdak (1930-), for his significant contribution in the study of minerals in the Jachymov ore district. |
Synonym: |
IMA1998-031 |
| | Vajdakite Image
Images:
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Vajdakite Crystallography Axial Ratios: |
a:b:c =0.5832:1:1.0106 |
Cell Dimensions: |
a = 7.0515, b = 12.0908, c = 12.219, Z = 4; beta = 101.268° V = 1,021.69 Den(Calc)= 3.48 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 21/c |
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), |
Crystal Structure:
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Mouse
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| Physical Properties of Vajdakite Cleavage: |
{100} Perfect, {010} Good |
Color: |
Green, Greenish gray. |
Density: |
3.5 |
Diaphaneity: |
Translucent |
Habit: |
Acicular - Occurs as needle-like crystals. |
Habit: |
Aggregates - Made of numerous individual crystals or clusters. |
Luster: |
Vitreous (Glassy) |
Streak: |
light grayish green |
| Optical Properties of Vajdakite 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 Optical Data: |
Biaxial (+), a=1.757, b=1.778, g=2.04, bire=0.2830 |
| Calculated Properties of Vajdakite Electron Density: |
Bulk Density (Electron Density)=3.28 gm/cc |
note: Specific Gravity of Vajdakite =3.50 gm/cc. Fermion Index: |
Fermion Index = 0.08 |
Boson Index = 0.92 Photoelectric: |
PEVajdakite = 74.94 barns/electron |
U=PEVajdakite x rElectron Density= 245.66 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Vajdakite is Not Radioactive | Vajdakite Classification Dana Class: |
49.04.08.01 (49)Basic and Hydrated Molybdates and Tungstates |
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(49.04)(Compound Anions) |
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(49.04.08)Dana Group |
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Strunz Class: |
04.JC.20 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate |
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04.J - Arsenites, Antimonites, Bismuthites, Sulfites, |
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04.JC -Arsenites, antimonites, bismuthites; without additional anions, with H2O |
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| Other Vajdakite Information References: |
NAME( AmMin, Vol 87, p 983) PHYS. PROP.(AmMin, Vol 87, p 983) OPTIC PROP.(AmMin, Vol 87, p 983) |
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 Search for Vajdakite using: Visit our Advertisers for Vajdakite : A Bijoux Google Search for VajdakiteAdam's Minerals Google Search for Vajdakite Cape Minerals Google Search for Vajdakite Dakota Matrix Minerals Google Search for Vajdakite Excalibur Mineral Corp. Google Search for Vajdakite Exceptional Minerals Google Search for Vajdakite John Betts Fine Minerals Search for Vajdakite McDougall Minerals Google Search for Vajdakite Mineral News Website Link Rock and Mineral Shows Google Search for Vajdakite Weinrich Minerals, Inc. Google Search for Vajdakite Ask about Vajdakite here : Print or Cut-and-Paste your Vajdakite Specimen Label here :
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