Ishikawaite

 IMA-GP
Uranium 8.1.4.1
(Dana Classification Number)
(No Images) 4/D.19-70
(Strunz ID)

Property Data Remarks
Named for: Ishikawa district, Iwaki, Fukushima Prefecture, Tohoku Region, Honshu Island, Japan, its type locality
Alternate
    Name(s):
  		•  
    Mineral Class:
    Oxides
      Oxides with metal: (metal:oxygen = 1:2)
    (MO2 and related compounds)
        Polycrase-(Y) - Loranskite-(Y) series
    		 
    Chemical
        Formula:    		 (U,Fe,Y,Ca)(Nb,Ta)O4  
    Chemical
        Composition:
    Calcium: (Ca) 1.36%
    Iron: (Fe) 7.59%
    Niobium: (Nb) 23.66%
    Oxygen: (O) 21.73%
    Tantalum: (Ta) 15.36%
    Yttrium: (Y) 6.04%
    Uranium: (U) 24.25%
    		by weight
    Molecular
        Weight:    		 294.45 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    4.3410 × 1004 1.17 × 10-06 0.59 5.95

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Orthorhombic
    Axial Ratios: a:  
    b:  
    c:  
    Cell Dimensions: a:   Å
    b:   Å
    c:   Å
    Z:  
    a:   °
    b:   °
    g:   °
    V:   Å3
    DenCalc:  
    H-M Symbol:  
    Space Group:  
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1):   Å
    (0.):   Å
    (0.):   Å
    		 
    Habit:
  		•  
    Cleavage: None  
    Fracture: Brittle - Conchoidal  
    Moh's
        Hardness:    		 5 - 6  
    Density: 6.2 - 6.4 grams/cm3
    Color: Black  
    Streak: Dark brown  
    Luster: Resinous  
    Diaphaneity: Opaque  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • In pegmatites
    		•   
    Associated
        Minerals:

    Albite, Allanite-(Ce), Almandine, Autunite, Bertrandite, Beryl, Biotite, Bismuthinite, Bismutite, 'Columbite', Hematite, Ilmenite, Magnetite, Meta-autunite, Microcline, Microlite, Monazite-(Ce), Muscovite, 'Oligoclase', Opal var: Hyalite, Pyrite, Quartz, Quartz var: Smoky Quartz, Samarskite, Schorl, Uraninite

    Mineral   -   > 57% of sites
    Mineral   -   > 28% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Ishikawaite
    Localities:

    Very Rare

    Ishikawaite Localities
    Notes:

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

    Crystals are probably metamic.