Phurcalite

 IMA-A 1977-040
Uranium 42.4.7.1
(Dana Classification Number)
(Images) 7/E.07-40
(Strunz ID)

Property Data Remarks
Named for: Its Phosphorus, Calcium and Uranium content
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:    		 Ca2(UO2)3O2(PO4)2 · 7H2O  
    Chemical
        Composition:
    Calcium: (Ca) 6.47%
    Hydrogen: (H) 1.14%
    Oxygen: (O) 29.72%
    Phosphorus: (P) 5.00%
    Uranium: (U) 57.67%
    		by weight
    Molecular
        Weight:    		 1,238.29 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    1.03224 × 1005 2.79 × 10-06 1.42 141.99

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Orthorhombic - Dipyramidal
    Axial Ratios: a: 1.086
    b: 1
    c: 0.848
    Cell Dimensions: a: 17.415 Å
    b: 16.035 Å
    c: 13.598 Å
    Z: 8
    V: 3,797.24 Å3
    DenCalc: 4.33
    H-M Symbol: 2/m 2/m 2/m
    Space Group: Pbca
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 8.05 Å
    (0.8): 3.09 Å
    (0.8): 3.1 Å
    		 
    Habit:
  • Acicular
  • Radiating groups
  • Botryoidal masses from hydrothemal action on radial clusters
    		•   
    Cleavage:
    [001] Perfect
    [010] Perfect
    [100] Good
    		 
    Fracture:    
    Moh's
        Hardness:    		 3  
    Density: 4.22 grams/cm3
    Color: Yellow  
    Streak: Yellow white  
    Luster: Vitreous - Adamantine  
    Diaphaneity: Translucent (One Specimen Examined)
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  		•  
    Associated
        Minerals:

    Autunite, Barite, Billietite, Brochantite, Dewindtite, Kasolite, Metatorbernite, Phosphuranylite, Studtite, Torbernite, Uraninite, Uranocircite, Uranophane, Wolsendorfite, Zeunerite

    Mineral   -   > 50% of sites
    Mineral   -   > 25% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Phurcalite
    Locations:

    Very rare

    Phurcalite Locations
    Notes:

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

    Phurcalite Images

    Specimen #1
    (001a) (001b) (001c) (001d)
    Posey Mine, White Canyon District, San Juan Co., Utah, U.S.A.

    Specimen Notes

    Occurrence - The Phurcalite occurs on top of clusters of Aragonite crystals. The Aragonite occurs in turn on a fine grained light gray sandstone. The Purcalite gives the appearance of once having been radial clusters that were 'melted' into botryoidal masses by hydrothermal action.

    The Phurcalite does not occur on, or in contact with, the sandstone. Other occurrances of Phurcalite do occur on sandstone, so this isolation from the sandstone by growing on Aragonite is not a habit.

    Crystals - No intact crystals can be seen.

    Appearence - The general appearance of the Phurcalite on Aragonite is of 'eggs fried sunny-side-up' under the microscope at 30X.

    Diaphaniety - The Phurcalite appears to be transluscent.

    Luster - The Phurcalite has a dull, earthy luster, likely from the process of 'melting' into solid masses. There are a few glints of what appears to be adamantine luster throughout the Phurcalite.

     

      -  

     

    Specimen Physical Properties
    Size   cm   cm   cm
    Weight: x grams    
    g-Radiation Level:   cmp   msieverts background: 20 cpm