Thorite

 IMA-GP
Thorium 51.5.2.3
(Dana Classification Number)
(Images) 8/A.09-30
(Strunz ID)

Property Data Remarks
Named for: Thor, the Scandinavian god of war.
Alternate
    Name(s):
  • Orangite
  • Uranothorite (?)
    		•   
    Mineral Class:
    Silicates
      Nesosilicates with [SiO4]-4 groups,
    cations of octahedral and cubic orientation [8+6]
        Zircon - Thorogummite series
    		 
    Chemical
        Formula:    		 (Th, U)SiO4  
    Chemical
        Composition:
    Oxygen: (O) 19.74%
    Silicon: (Si) 8.67%
    Thorium: (Th) 71.59%

    by weight

    (Uranium in trace amounts)
    Molecular
        Weight:    		 324.12 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    3.2072 × 1004 8.67 × 10-07 0.42 42.14

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Tetragonal - Ditetragonal Dipyramidal
    Axial Ratios: a:b:c = 1:0.8845
    Cell Dimensions: a = 7.117, c = 6.295, Z = 4; V = 318.85 Den(Calc)= 6.75
    H-M Symbol: 4/m 2/m 2/m
    Space Group: I41/amd
    X Ray Diffraction: By Intensity(I/Io): 3.53(1) 4.69(0.9) 2.65(0.8)
    		Thorite
    Crystals
    Habit:
  • Prismatic
  • Granular
  • Massive
    		•   
    Cleavage:
    [001]
    [010]
    [110] Poor
    		 
    Fracture: Conchoidal.  
    Moh's
        Hardness:    		 4 - 4.5 - 5  
    Density: 4 - 4.1 - 6.7 - 7 grams/cm3
    Color: Brown to dark brown, brownish black, brownish yellow, yellow, orange-yellow or orange.  
    Streak: Light brown, white, grey or orange.  
    Luster: Resinous  
    Diaphaneity: Subtransparent to subtranslucent, opaque  
    Diochroism:
    (e): None
    (w:) None
    		 
    Ultra Violet
        Fluorescence:
    Long Wave: None
    Short Wave: None
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • Pegmatites
  • Augite-syenite rocks
  • aluvial deposits
    		•   
    Associated
        Minerals:

    Aegirine, Albite, 'Allanite', 'Apatite', Barite, Biotite, Calcite, Chalcopyrite, Fluorite, Galena, Goethite, Hematite, Ilmenite, Magnetite, Microcline, Molybdenite, Monazite-(Ce), Muscovite, Nepheline, Pyrite, Pyrochlore, Quartz, Rutile, Titanite, Zircon

    Mineral   -   > 67% of sites
    Mineral   -   > 50% of sites
    Mineral   -   > 25% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Thorite
    Locations:

    Relatively common Uranium mineral

    Thorite Locations
    Notes:

    Strongly radioactive (a- and b-particles, g-rays). Almost always metamict (a substance in an amorphous state, having lost its crystalline structure as a result of radioactivity).

    The most common mineral of thorium and a minor ore of uranium.

    Thorite Images

    Specimen #1
       
      w. Zircon
    Wichita Mts., Oklahoma, USA    		  

    Specimen #2
    (003-col) (003a) (003ca) (003cb)
    (003b) (003da) (003db)  
     
    Balangoda, Ratnapura, Sabaragamuwa province, Sri Lanka