Yttropyrochlore-(Y)

 IMA-A 1977-SUB
Uranium 8.2.1.4
(Dana Classification Number)
(No Images) 4/C.17-60
(Strunz ID)

Property Data Remarks
Named for: Being the Yttrium-dominent member ot the pyrochlore group
Alternate
    Name(s):
  • Obruchevite
    		•   
    Mineral Class: Oxides & Hydroxides -
    - Pyrochlore group, Pyrochlore series with Nb > Ti    		  
    Chemical
        Formula:    		 (Y,Na,Ca,U)1-2(Nb,Ta,Ti)2(O,OH)7  
    Chemical
        Composition:
    Calcium: (Ca) 1.76%
    Hydrogen: (H) 0.62%
    Iron: (Fe) 1.22%
    Niobium: (Nb) 24.45%
    Oxygen: (O) 24.91%
    Sodium: (Na) 1.01%
    Tantalum: (Ta) 19.84%
    Titanium: (Ti) 2.10%
    Uranium: (U) 10.44%
    Yttrium: (Y) 13.65%
    		by weight
    Molecular
        Weight:    		 455.99 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    1.8688 × 1004 5.05 × 10-07 0.26 26.20

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Isometric - Hextetrahedral
    Axial Ratios: a:b:c = ::
    Cell Dimensions: a = 10.2, Z = 6; V = 1,061.21 Den(Calc) = 4.28
    H-M Symbol: -4 3m
    Space Group: Fd3m
    X Ray Diffraction: By Intensity(I/Io): 2.95(1) 3.02(1) 3.09(0.25)
    		 
    Habit:
  • Massive
  		•   
    Cleavage: None  
    Fracture: Brittle - Conchoidal  
    Moh's
        Hardness:    		 4.5 - 5.5  
    Density: 3.6 - 3.8 grams/cm3
    Color: Dark brown  
    Streak: Light brown  
    Luster: Resinous  
    Diaphaneity: Translucent to Opaque  
    Pleochroism:
    (x):
    (y:)
    (z:)
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:
    Short Wave:
    		 
    Magnetism: Non-magnetic  
    Occurance:
    • Replacement zones in a pegmatite
    		  
    Associated
        Minerals:

    Albite, 'Allanite', 'Apatite', Bertrandite, Beryl var: Bazzite, Betafite, Cascandite, Cassiterite, 'Columbite', 'Columbite-Tantalite', Epidote, Fluorite, 'Gadolinite', 'Garnet Group', Hingganite-(Y), Ixiolite, 'Kristiansenite', Magnetite, Microcline, Microcline var: Amazonite, Microlite, Milarite, 'Monazite', Muscovite, Plumbomicrolite, Pyrochlore, Quartz, Rutile var: Ilmenorutile, Scandiobabingtonite, Spessartine, Stilpnomelane, Xenotime-(Y), Yttrobetafite-(Y), Zircon

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

    		These are minerals known to be found with Yttropyrochlore-(Y)
    Locations:

    Very rare

    Yttropyrochlore-(Y) Locations
    Notes:

    Somewhat radioactive (a- and b-particles, g-rays).

    Crystals are probably metamic.