Oursinite

 IMA-A 1982-051
Uranium 53.3.1.7
(Dana Classification Number)
(No Images) 8/B.34-30
(Strunz ID)

Property Data Remarks
Named for: The French "oursin", sea urchin, in allusion to the radiating habit of the acicular crystals
Alternate
    Name(s):
  		•  
    Mineral Class:
    Silicates
      NesosilicatesNesosilicates
    "Insel" silicates with anions unfamiliar to tetraheders.
    Uranyl-"Insel" silicates with [UO2]2+ - [SiO4]4-
        Sklodowskite - Uranophane - Kasolite series
    		 
    Chemical
        Formula:    		 (Co,Mg)(H3O)2[(UO2)SiO4]2 · 3H2O  
    Chemical
        Composition:
    Cobalt: (Co) 6.08%
    Hydrogen: (H) 1.39%
    Magnesium: (Mg) 0.28%
    Oxygen: (O) 31.20%
    Silicon: (Si) 6.44%
    Uranium: (U) 54.61%
    		by weight
    Molecular
        Weight:    		 871.78 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    9.7747 × 1004 2.64 × 10-06 1.35 135.34

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Orthorhombic
    Axial Ratios: a: 0.7259
    b: 1
    c: 0.4017
    Cell Dimensions: a: 12.74 Å
    b: 17.55 Å
    c: 7.05 Å
    Z: 4
    V: 1,576.29 Å3
    DenCalc: 3.67
    H-M Symbol:  
    Space Group: Aba2, Abam
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 8.73 Å
    (0.9): 2.853 Å
    (0.7): 7.2 Å
    		 
    Habit:
  • Acicular
  • Radial
  • Aggregates
    		•   
    Cleavage:
    [???] Good
    		 
    Fracture:    
    Moh's
        Hardness:    		 3 - 3.5  
    Density: 3.67 grams/cm3
    Color: Yellow  
    Streak:    
    Luster: Vitreous  
    Diaphaneity: Transparent to Translucent  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • The oxidation zones of uranium ores
    		•   
    Associated
        Minerals:

    Barite, Becquerelite, Bijvoetite-(Y), Billietite, Carrollite, Cattierite, Chernikovite, Cobaltoan Calcite, Comblainite, 'Cousinite', Cuprosklodowskite, Curienite, Curite, Dewindtite, Dumontite, Fourmarierite, Guilleminite, Gysinite-(Nd), Ianthinite, Kasolite, Lepersonnite-(Gd), Liebigite, Masuyite, Metaschoepite, Metastudtite, Metatorbernite, Metavandendriesscheite, Paraschoepite, Parsonsite, Phosphuranylite, Phurcalite, Piretite, Platinum, Protasite, Richetite, Roubaultite, Rutherfordine, Saléeite, Sayrite, Schmitterite, Schoepite, Sengierite, Sharpite, Sklodowskite, Soddyite, Studtite, Torbernite, Umohoite, Urancalcarite, Uraninite, Uranophane, Vaesite, Vandenbrandeite, Vandendriesscheite, Wolsendorfite, Wyartite, Zippeite

    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Oursinite
    Locations:

    Extremely rare

    Oursinite Locations
    Notes:

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

    Crystals are probably metamic.