Dessauite-(Y)

 IMA-A 1994-057
Uranium 8.5.1.9
(Dana Classification Number)
(No Images) 4/C.09-45
(Strunz ID)

Property Data Remarks
Named for: Gabor Dessau (1907-1983), professor of ore mineralogy at the University of Pisa, Italy
Alternate
    Name(s):
  • Romanite
    		•   
    Mineral Class:
    Oxides
      Oxides with metal: [metal:oxygen = 2:3 (M2O3 and related compounds)]
        Crichtonite group
    		 
    Chemical
        Formula:    		 (Sr,Pb)(Y,U)(Ti,Fe+2)20O38
    or:
    (Sr,Pb)(Y,U)Fe+32(Ti,Fe+3)18O38    †     		  
    Chemical
        Composition:
    Iron: (Fe) 15.04%
    Lead: (Pb) 2.79%
    Oxygen: (O) 32.75%
    Strontium: (Sr) 3.54%
    Titanium: (Ti) 38.68%
    Uranium: (U) 3.85%
    Yttrium: (Y) 3.35%
    		by weight
    Molecular
        Weight:    		 1,856.57 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    6.885 × 1003 1.86 × 10-07 0.10 10.08

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Trigonal - Rhombohedral
    Axial Ratios: a: 1
    c: 2.01454
    Cell Dimensions: a: 10.385 Å
    c: 20.921 Å
    Z: 6 (3    † )
    V: 1,954.01 Å3
    DenCalc: 4.89 (4.68    † )
    H-M Symbol: -3
    Space Group: P-3 (R-3    † )
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (0.6): 3.41 Å    † 
    (0.6): 2.90 Å    † 
    (0.6): 1.603 Å    † 
    (0.6): 1.441 Å    † 

    Note: only medium and weak x-ray diffraction lines.

    		 Dessauite
    Crystal
    Habit:
  • Flattened rhombohedral crystals < 1 mm having a hexagonal appearance    † 
    		•   
    Cleavage: None  
    Fracture: Conchoidal  
    Moh's
        Hardness:    		 6.5 - 7  
    Density: 4.68 grams/cm3
    Color: Black, (ash-gray with pale bluish tinges    † )  
    Streak: Black  
    Luster: Metallic  
    Diaphaneity: Opaque  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • In calcite veins within dolomite. A member of the Crichtonite group.
    		•   
    Associated
        Minerals:

    'Allanite', Anatase, Apuanite, Barite, Beryl, Boulangerite, Bournonite, Calcite, Chalcostibite, 'Chlorite', Cinnabar, Derbylite, Diadochite, Dolomite, Galena, Gersdorffite, Hematite, Karelianite, Magnetite, Malachite, Muscovite, Pillaite, Pyrite, Quartz, Robinsonite, Rutile, 'Scainite', Schafarzikite, Seligmannite, Siderite, Sorbyite, Spessartine, Sphalerite, Stibivanite, Stibnite, Stolzite, Tetrahedrite, Tintinaite, Vanadinite, Versiliaite, Vivianite, Zinkenite

    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Dessauite
    Localities:

    Extremely rare

    Dessauite Localities
    Notes:

    Radioactive a- and b-particles, g-rays.

    Crystals are probably metamic.

     †  J.H. Bernard and J. Hyrsl, Minerals and their Localities.