meta-Uranocircite

 IMA-GP
Uranium 40.2a.3.2
(Dana Classification Number)
(Images) 7/E.02-110
(Strunz ID)

Property Data Remarks
Named for: Its composition and its being the meta- form of Uranocircite, named for the Greek word for falcon - refering to Falkenstein, Saxony, Germany - where it is commonly found.
Alternate
    Name(s):
  		•  
    Mineral Class:
    Phosphates, Arsenates and Vanadates
      Uranylphosphates and Uranylvanadates with
    [UO2]2+ - [PO4 | AsO4]3- and
    [UO2]2+ - [V2O8]6-
        Meta-Autunite group
    		 
    Chemical
        Formula:    		 Ba(UO2)2(PO4)2 · 6-8H2O  
    Chemical
        Composition:
    Barium: (Ba) 13.82%
    Hydrogen: (H) 1.42%
    Oxygen: (O) 30.60%
    Phosphorus: (P) 6.24%
    Uranium: (U) 47.92%
    		by weight
    Molecular
        Weight:    		 993.43 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    8.5778 × 1004 2.32 × 10-06 1.18 117.88

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Monoclinic - Sphenoidal (pseudotetragonal)
    Axial Ratios: a: 1.0101
    b: 1
    c: 1.7261
    Cell Dimensions: a: 9.855 Å
    b: 9.756 Å
    c: 16.84 Å
    Z: 4
    b: 90.6°
    V: 1,619.00 Å3
    DenCalc: 4.08
    H-M Symbol: 2
    Space Group: P21
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 3.6 Å
    (0.9): 8.34 Å
    (0.4): 4.23 Å
    Surface markings: Very pronouced striations aligned to one edge, or rarely at 45o to both edges. The internal markings are parallel to one axis and orthogonal to the surface striations. Occassional internal markings are at 45o to the face axes of the crystal, and are usually more pronounced.
    		 
    Habit:
  • Square tabular crystals dominated by two pinacoid faces. Pseudomorph of uranocircite.
  • Crystal symmetry is monoclinic, but outwardly appears to be tetragonal (i.e. pseudotetragonal)
  • Crystals may also look cubic (pseudocubic)
  • Crusts
  • Micaceous
  • Foliated
  • Earthy
    		•   
    Cleavage:
    [001]  
    [010]  
    [100]  

    Cleavage sheets are brittle

    		  
    Fracture: Uneven  
    Moh's
        Hardness:    		 2 - 2.5  
    Density: 3.95 - 4.1 grams/cm3
    Color: Yellow to Yellow-green  
    Streak: Pale yellow  
    Luster: Pearly - Vitreous - Dull  
    Diaphaneity: Transparent - Translucent - Opaque  
    Pleochroism:
    (x): Colorless
    (y:) Colorless
    (z:) Colorless
    		 
    Ultra Violet
        Fluorescence:
    Long Wave: Green to yellowish green
    Short Wave: Green to yellowish green
    		Long wave UV fluorescence may be slightly stronger than short wave UV
    Magnetism: Non-magnetic  
    Occurance:
  • Found in some petrified wood in Arizona
    		•   
    Associated
        Minerals:

    Autunite, Barite, Bassetite, Bornite, Brochantite, Calcite, Chalcocite, Chalcopyrite, Chrysocolla, Coffinite, Covellite, Curite, Dewindtite, Dolomite, Fluorite, Galena, Goethite, Gypsum, Hematite, Hemimorphite, Johannite, Kasolite, Lepidocrocite, 'Limonite', Malachite, Marcasite, Meta-Autunite, Metatorbernite, Phosphuranylite, Pyrite, Quartz, Quartz var: Chalcedony, Schoepite, Sklodowskite, Sulphur, Torbernite, Uraninite, Uranocircite, Uranophane, Uranophane-beta, Uranopilite, Zippeite

    Mineral   -   > 64% of sites
    Mineral   -   > 45% of sites
    Mineral   -   > 27% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with meta-Uranocircite
    Locations:

    Rare

    meta-Uranocircite Locations
    Notes:

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

    Meta-uranocircite is a dehydration product of Uranocircite. Involving the loss of only a few water molecules, a good pseudomorph is likely to be produced. Collected samples of Uranocircite may be concidered to have become meta-Uranocircite after a few years.

    Differentiate from uranocircite by its density and brittle cleavage sheets.

    meta-Uranocircite Images

    Specimen #1
      (001a) (001b)  
       
    (001c) (001d) (001e) (001f)
    (001g) (001h) (001i) (001m)
    Crystal fragments showing the 100, 010 and 110 cracking due to meta-formation. Note the unusual 210 and 410 fractures.
    (001k) (001l) (001j)
    Les Bois-Noirs Mine, St Priest-la-Prugne, Loire, Rhône-Alpes, France

    Specimen Notes

    Occurrence -  

     

    Crystals -  

     

    Appearence -  

    Diaphaniety -

    Luster -

     

      -  

     

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