Torbernite

 IMA-GP
Uranium  
(Dana Classification Number)
(No Images) 7/E.01-70
(Strunz ID)
Unless sealed in glass, all specimens should be considered to have become Metatorbernite within a few months of being exposed to ambient air.

Property Data Remarks
Named for: Torber Bergmann (1735-1784), Swedish chemist
Alternate
    Name(s):
  • Copper Uranite
    		•   
    Mineral Class:
    Phosphates, Arsenates and Vanadates
      Uranylphosphates and uranylvanadates with
    [UO2]2+ - [PO4 | AsO4]3- and
    [UO2]2+ - [V2O8]6-
        Autunite group
    		 
    Chemical
        Formula:    		 Cu(UO2)2(PO4)2 · 10H2O  
    Chemical
        Composition:
    Copper: (Cu) 6.41%
    Hydrogen: (H) 2.24%
    Oxygen: (O) 37.11%
    Phosphorus: (P) 6.25%
    Uranium: (U) 48.00%
    		by weight
    Molecular
        Weight:    		 991.71 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    8.5926 × 1004 2.32 × 10-06 1.22 121.81

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Tetragonal - Ditetragonal Dipyramidal
    (Crystals can look cubic, but the pearly luster only on the pinacoid faces gives the true symmetry away)
    Axial Ratios: a:b:c = 1:2.90934
    Cell Dimensions: a = 7.06, c = 20.54, Z = 2; V = 1,023.79 Den(Calc)= 3.22
    H-M Symbol: 4/m 2/m 2/m
    Space Group: I4/mmm
    X Ray Diffraction: By Intensity(I/Io): 10.3(1) 3.58(0.9) 4.94(0.9)
    		Torbernite
    Crystals
    Habit:
  • Tabular - square crystals dominated by two pinacoid faces. Crystals can form in parallel growths giving a "stacked book" kind of look. Faint striations parallel to either, or both, of the two pinacoid axis's, can sometimes be seen. The striations are most prominent on the edges. These striations have not been seen at any other angle.
  • Crusts - earthy or clay-like
  • Micaceous
  • Foliated
  • Scaly aggregates
    		•   
    Cleavage:
    [001] Perfect
    [010]
    [100] Distinct
    		Cleavage sheets are not bendable but are in fact brittle.
    Fracture: Brittle - uneven  
    Moh's
        Hardness:    		 2 - 2.5  
    Density: 3.2 - 3.7 - 3.8 grams/cm3
    Color: Various shades of dark to light green  
    Streak: Pale to Light green  
    Luster: Vitreous to Pearly (adamantine on the main pinacoid)  
    Diaphaneity: Transparent to Translucent  
    Pleochroism:
    (x): None
    (y:) None.
    (z:) None.
    		 
    Ultra Violet
        Fluorescence:
    Long Wave: Usually none
    (rarely - weakly yellow)
    Short Wave: Usually none
    (rarely - weakly yellow)
    		 
    Magnetism: Non-magnetic  
    Occurance:

    Alteration of uraninite and pitchblende

    		  
    Associated
        Minerals:

    Arsenopyrite, Autunite, Beryl, Chalcopyrite, Cuprosklodowskite, Fluorapatite, Fluorite, Galena, Hematite, Malachite, Meta-Autunite, Metatorbernite, Muscovite, Pyrite, Quartz, Schorl, Sphalerite, Uraninite, Uranocircite, Uranophane

    Mineral   -   > 20% of sites
    Mineral   -   > 40% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Torbernite
    Locations:

    One of the most common uranium minerals

    Torbernite Locations
    Notes:

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

    Torbernite can lose water and convert to a different mineral called meta-torbernite, of the meta-autunite/meta-torbernite group of minerals. The change to meta-torbernite will often produce a pseudomorph.

    Non-fluorescence best distinguishes this mineral from Autunite. See Metatorbernite Specimen #1 of an example of Autunite and Metatorbernite intergrowing into each other.