Vanmeersscheite

 IMA-A 1981-009
Uranium 42.7.14.1
(Dana Classification Number)
(No Images) 7/E.07-140
(Strunz ID)
Unless sealed in glass, all specimens should be considered to have become Metavanmeersscheite within a few months of being exposed to ambient air.

Property Data Remarks
Named for: Maurice Van Meerssche, Belgian crystallographer, Professor at the University of Louvain-la-Neuve, Belgium.
Alternate
    Name(s):
  		•  
    Mineral Class:
    Phosphates, Arsenates and Vanadates
      Uranylphosphates and uranylvanadates with
    [UO2]+2 - [PO4 | AsO4]-3 and
    [UO2]+2 - [V2O8]-6
        Phosphuranylite series
    		 
    Chemical
        Formula:    		 U+6(UO2)3(PO4)2(OH)6 · 4H2O  
    Chemical
        Composition:
    Hydrogen: (H) 1.00%
    Oxygen: (O) 27.19%
    Phosphorus: (P) 4.39%
    Uranium: (U) 67.42%
    		by weight
    Molecular
        Weight:    		 1,412.16 daltons (amu)
    Specific
        Radioactivity:

    (All radiation is for a 1 gram, fully aged specimen)

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    1.20687 × 1005 3.26 × 10-06 1.62 161.63

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Orthorhombic - Pyramidal
    Axial Ratios: a:b:c = 1.0178:1:0.419
    Cell Dimensions: a = 17.06, b = 16.76, c = 7.023, Z = 4; V = 2,008.06 Den(Calc)= 4.67
    H-M Symbol: mm2
    Space Group: Pmn21
    X Ray Diffraction: By Intensity(I/Io): 8.39(1) 5.96(0.8) 4.18(0.7)
    		 
    Habit:
  		•  
    Cleavage:
    [001]
    [010] Good
    [100] Indistinct
    		 
    Fracture:    
    Moh's
        Hardness:    		 2 - 3  
    Density: 4.67 grams/cm3
    Color: Canary yellow  
    Streak: Light yellow  
    Luster:    
    Diaphaneity:    
    Pleochroism:
    (x):
    (y:)
    (z:)
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:
    Short Wave:
    		 
    Magnetism: Non-magnetic  
    Occurance:
  		•  
    Associated
        Minerals:

    Arsenopyrite, Autunite, Bismuth, Chalcopyrite, Cookeite, Fluorite, Goethite, Hematite, Löllingite, Meta-Autunite, Metatorbernite, Montebrasite, Phosphuranylite, Pyrite, Quartz, Rutherfordine, Saléeite, Studtite, Torbernite, Uraninite, Uranophane, Uranophane-beta, Vanmeersscheite, Wolsendorfite

    Mineral   -   all sites
    Mineral   -   > 65% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Vandendriesscheite
    Locations:

    Very rare

    Vandendriesscheite Locations
    Notes:

    Strongly radioactive a- and b-particles, g-rays.

    Crystals are probably metamic.