Dumontite

 IMA-GP
Uranium 42.4.5.1
(Dana Classification Number)
(No Images) 7/E.07-90
(Strunz ID)

Property Data Remarks
Named for: André Dumont (1809 - 1857), Belgian geologist.
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:    		 Pb2(UO2)3O2(PO4)2 · 5H2O  
    Chemical
        Composition:
    Hydrogen: (H) 0.66%
    Lead: (Pb) 26.97%
    Oxygen: (O) 21.87%
    Phosphorus: (P) 4.03%
    Uranium: (U) 46.47%
    		by weight
    Molecular
        Weight:    		 1,536.50 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    8.3190 × 1004 2.25 × 10-06 1.10 10.99

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Monoclinic - Prismatic
    Axial Ratios: a: 0.4877
    b: 1
    c: 0.4196
    Cell Dimensions: a: 8.16 Å
    b: 16.73 Å
    c: 7.02 Å
    Z: 110
    b: 110°
    V: 900.55 Å3
    DenCalc: 5.67
    H-M Symbol: 2/m
    Space Group: P21/m
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 4.27 Å
    (0.85): 2.94 Å
    (0.85): 3 Å
    		 
    Habit:
  		•  
    Cleavage:
    [???] Perfect
    		 
    Fracture:    
    Moh's
        Hardness:    		 2 - 3  
    Density: 5.65 grams/cm3
    Color: Golden brown  
    Streak: Light yellow  
    Luster:    
    Diaphaneity: Translucent  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  		•  
    Associated
        Minerals:

    Autunite, Barite, Becquerelite, Cuprosklodowskite, Curite, Dewindtite, Fluorite, Fourmarierite, Galena, Ianthinite, Johannite, Kasolite, Metatorbernite, Parsonsite, Phosphuranylite, Rutherfordine, Saléeite, Schoepite, Sklodowskite, Studtite, Torbernite, Uraninite, Pitchblende, Uranocircite, Uranophane, Wolsendorfite, Wulfenite, Wyartite, Zippeite

    Mineral   -   > 60% of sites
    Mineral   -   > 30% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Dumontite
    Localities:

    Rare

    Dumontite Localities
    Notes:

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

    Crystals are probably metamic.