Petscheckite

 IMA-A 1975-038 & 1978
Uranium
Thorium		 8.1.9.2
(Dana Classification Number)
(No Images) 4/D.23-10
(Strunz ID)

Property Data Remarks
Named for: Eckhard Petsch (1939-), of Idar-Oberstein, Germany, who was a noteworthy prospector in Madagascar
Alternate
    Name(s):
  • Hydroxypetscheckite
  • Oxypetscheckite
    		•   
    Mineral Class:
    Oxides
      Oxides with metal:
    (metal:oxygen = 1:2 (MO2) and related compounds)
        Petscheckite - Liandratite series
    		 
    Chemical
        Formula:    		 U+4Fe+2(Nb,Ta)2O8  
    Chemical
        Composition:
    Iron: (Fe) 8.57%
    Niobium: (Nb) 21.38%
    Oxygen: (O) 19.64%
    Tantalum: (Ta) 13.88%
    Uranium: (U) 36.52%
    		by weight
    Molecular
        Weight:    		 651.70 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    6.5378 × 1004 1.77 × 10-06 0.88 87.95

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Trigonal - Hexagonal Scalenohedral
    Axial Ratios: a: 1
    c: 0.62616
    Cell Dimensions: a: 6.42 Å
    c: 4.02 Å
    Z: 1
    V: 143.49 Å3
    DenCalc: 6.21
    H-M Symbol: -3 2/m
    Space Group: P-31m
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 3.21 Å
    (1): 4.02 Å
    (0.8): 2.51 Å
    		 
    Habit:
  		•  
    Cleavage: None  
    Fracture:    
    Moh's
        Hardness:    		 5  
    Density: 5.5 grams/cm3
    Color: Black  
    Streak: Brown black  
    Luster: Metallic  
    Diaphaneity: Opaque  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • Petscheckite is hypothesized on theoretical grounds, having altered to oxypetscheckite and hydroxypetscheckite
    		•   
    Associated
        Minerals:

    Liandratite

    Minerals   -   Uranium & Thorium
    mineral links

    		This is the only mineral listed to be found with Petscheckite
    Locations:

    Extremely rare

    Petscheckite Locations
    Notes:

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

    Crystals are probably metamic.