Margaritasite

 IMA-A 1980-093
Uranium  
(Dana Classification Number)
(Images) 7/E.11-60
(Strunz ID)

Property Data Remarks
Named for: Margaritas deposit, Pena Blanca District, Chihuahua, Mexico, its type locality
Alternate
    Name(s):
  		•  
    Mineral Class:
    Phosphates, Arsenates and Vanadates
      Uranylphosphates and uranylvanadates with:
    [UO2]+2 - [PO4 | AsO4]-3 and [UO2]+2 - [V2O8]-6,
    uranyl-group vanadates with [UO2]+2 - [V2O8]-6
        Tyuyamunite series
    		 
    Chemical
        Formula:    		 (Cs,K,H3O)2(UO2)2V2O8 · H2O  
    Chemical
        Composition:
    Cesium: (Ce) 16.36%
    Hydrogen: (H) 0.27%
    Oxygen: (O) 21.67%
    Potassium: (K) 2.41%
    Vanadium: (V) 10.45%
    Uranium: (U) 48.84%
    		by weight
    Molecular
        Weight:    		 974.70 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    8.7427 1004 2.36 10-06 1.17 116.72

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Monoclinic - Prismatic
    Axial Ratios: a: 1.2479
    b: 1
    c: 0.8605
    Cell Dimensions: a: 10.514 Å
    b: 8.425 Å
    c: 7.25 Å
    Z: 2
    b: 106.01°
    V: 617.30 Å3
    DenCalc: 5.24
    H-M Symbol: 2/m
    Space Group: P21/a
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 6.965 Å
    (0.7): 3.344 Å
    (0.7): 3.6 Å
    		 
    Habit:
  • Localized encrustations
  • microcrystals (?)
    		•  (One Specimen Examined)
    Cleavage:
    [001]  
    [010]  
    [100]  
    		 
    Fracture:    
    Moh's
        Hardness:    		 2  
    Density: 5.4 grams/cm3
    Color: Yellow  
    Streak: Light yellow  
    Luster: Earthy (One Specimen Examined)
    Diaphaneity: Opaque (One Specimen Examined)
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • Secondary mineral from uranium and vanadium minerals
    		•   
    Associated
        Minerals:

    Carnotite, Uraninite, Uranophane, Weeksite

    Mineral   -   67% of sites
    Mineral   -   33% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Margaritasite
    Locations:

    Extremely rare

    Margaritasite Locations
    Notes:

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

    Margaritasite Images

    Specimen #1
    (001a) (001b) (001c) (001d)
    (001e)
    Margaritas, Sierra Peña Blanca, Peña Blanca District, Chihuahua, Mexico

    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