Orthobrannerite

 IMA-A
Uranium 8.2.7.1
(Dana Classification Number)
(No Images) 4/D.22-30
(Strunz ID)

Property Data Remarks
Named for: G. Branner (1850-1922), geologist
Alternate
    Name(s):
  		•  
    Mineral Class:
    Oxides
      Oxides with metal:
    (metal:oxygen = 1:2 [MO2] and related compounds)
        Thorutite - Orthobrannerite series
    		 
    Chemical
        Formula:    		 U+4U+6Ti4O12(OH)2  
    Chemical
        Composition:
    Hydrogen: (H) 0.23%
    Oxygen: (O) 25.07%
    Titanium: (Ti) 21.43%
    Uranium: (U) 53.28%
    		by weight
    Molecular
        Weight:    		 893.59 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    9.5362 × 1004 2.58 × 10-06 1.29 128.98

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Orthorhombic - Disphenoidal
    Axial Ratios: a: 0.6315
    b: 1
    c: 0.5424
    Cell Dimensions: a: 7.37 Å
    b: 11.67 Å
    c: 6.33 Å
    Z: 2
    V: 544.43 Å3
    DenCalc: 5.45
    H-M Symbol: 2 2 2
    Space Group: P2122
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 3.17 Å
    (0.9): 1.659 Å
    (0.9): 2.45 Å
    		 
    Habit:
  • Prismatic crystals to ~1.2 cm in length
  • Crystals are horizontally striated
  • Usually metamict
    		•   
    Cleavage: None  
    Fracture: Conchoidal  
    Moh's
        Hardness:    		 4.5 - 5.5  
    Density: 5.46 grams/cm3
    Color: Brownish green, Black, Brown-black  
    Streak:

    Black, Brown-black to Brownish yellow

    (may have a light grayish-white surface coating. Red-brown internal reflections.)

    		  
    Luster: Adamantine  
    Diaphaniety: (Possibly translucent to transparent)  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • Weathered syenite (Yunnan Province, China)
  • Alkyline lamprophyre (Sichuan Province, China)
  • Gold ore veins (Brusson, Val d' Ayas, Valle d' Aosta, Italy)
    		•   
    Associated
        Minerals:

    'Anemousite', Azurite, Calcite, Cerussite, Chalcopyrite, 'Chlorite Group', Cosalite, Diopside, Epidote, Galena, 'Garnet Group', Gold, Malachite, Morenosite, Pyrite, Pyrrhotite, Quartz, Sphalerite, Tetrahedrite, Vesuvianite

    Minerals   -   Uranium & Thorium
    mineral links

    Based on Italy location only due to poor definition of China locations.

    		 These are minerals known to be found with Orthobrannerite
    Locations:

    Extremely rare

    Orthobrannerite Locations
    Notes:

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

    Crystals are probably metamic.