Richetite

 IMA-GP
Uranium 5.9.5.1
(Dana Classification Number)
(No Images) 4/H.07-60
(Strunz ID)

Property Data Remarks
Named for: Emile Richet (1884-1938), chief geologist, Union Miniere du Haut Katanga
Alternate
    Name(s):
  		•  
    Mineral Class:
    Oxides
      Uranyl ([UO2]+2) hydroxides and hydrates
        Fourmarierite - Masuyite series
    		 
    Chemical
        Formula:    		 PbU+64O13 · 4H2O

    Pb9[(UO2)18 | (OH)12 | O18 ] · 4H2O      †     		  
    Chemical
        Composition:
    Hydrogen: (H) 0.56% 0.26%    † 
    Lead: (Pb) 14.40% 60.22%    † 
    Oxygen: (O) 18.90% 8.78%    † 
    Uranium: (U) 66.15% 30.74%    † 
    		by weight
    Molecular
        Weight:    		 1,439.37 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    1.18405 × 1005 3.20 × 10-06 1.53 153.00

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System:   Triclinic
    Axial Ratios: a: 1.6666 1.7306  † 
    b: 1 1  † 
    c: 1.3515 1.3504  † 
    Cell Dimensions: a: 20.1 Å 20.94 Å  † 
    b: 12.06 Å 12.10 Å  † 
    c: 16.3 Å 16.34 Å  † 
    Z: 4 1  † 
    a: 103.8° 103.93°  † 
    b: 115.1° 115.4°  † 
    g: 90.4° 90.3°  † 
    V: 1,443.89 Å3  
    DenCalc: 6.62  
    H-M Symbol:    
    Space Group:   P1 or P-1 P1 or P-1  † 
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 3.122 Å 3.12 Å  † 
    (0.8): 7.12 Å 7.12 Å  † 
    (0.6): 3.55 Å 3.55 Å  † 
    (0.6):   3.47 Å  † 
    		 
    Habit:
  • Pseudo hexagonal crystals < 1 mm, flattened along {010} plane  † 
  • Tabular aggregates
    		•   
    Cleavage:
    [001] Perfect  
    [010] Fair Perfect  † 
    [100]  
    		 
    Fracture:    
    Moh's
        Hardness:    		 3.5  
    Density:   grams/cm3
    Color: Black, coffee Brown  
    Streak:    
    Luster: Adamantine  
    Diaphaneity: Translucent  †   
    Pleochroism:
    (x): Pale brown
    (y:) Dull brown
    (z:) Dull brown
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:
    Short Wave:
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • Oxidation product of Uraninite in the presence of lead  † 
    		•   
    Associated
        Minerals:

    Barite, Becquerelite, Cuprosklodowskite, Curienite, Dewindtite, Kasolite, Liebigite, Masuyite, Metaschoepite, Metatorbernite, Parsonsite, Phosphuranylite, Schoepite, Sklodowskite, Soddyite, Torbernite, Urancalcarite, Uraninite, Uranophane, Vandendriesscheite, Wolsendorfite, Zippeite

    Minerals   -   Important associate
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found at both sites with Richetite
    Locations:

    Very rare

    Richetite Locations
    Notes:

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

     †  J.H. Bernard and J. Hyrsl, Minerals and their Localities.

    Crystals are probably metamic.