Chevkinite-(Ce)

 IMA-GP
Thorium 56.2.8.1
(Dana Classification Number)
(Images) 8/C.07-210
(Strunz ID)

Property Data Remarks
Named for: General Konstatin Vladimirovich Tschevkin [Chevkin] (1802-1875), Chief of Staff, Russian Mining Engineers Corps
Alternate
    Name(s):
  • Clinochevkinite
  • Ferchevkinite
  • Tscheffkinite
    		•   
    Mineral Class:
    Silicates
      Sorosilicates with [Si2O7]-6,
    with anions unfamiliar to tetraheders [O,OH,F]
        Bertrandite - Strontiochevkinite series
    		 
    Chemical
        Formula:    		 (Ce,La,Ca,Th)4(Fe2+,Mg)2(Ti,Fe3+)3Si4O22  
    Chemical
        Composition:
    Calcium: (Ca) 2.66%
    Cerium: (Ce) 19.76%
    Iron: (Fe) 10.66%
    Lanthanum: (La) 16.13%
    Magnesium: (Mg) 0.40%
    Oxygen: (O) 29.20%
    Silicon: (Si) 9.32%
    Thorium: (Th) 1.93%
    Titanium: (Ti) 9.93%
    		by weight
    Molecular
        Weight:    		 1,205.27 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    862 2.33 × 10-08 0.01 1.24

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Monoclinic - Prismatic
    Axial Ratios: a: 2.3298
    b: 1
    c: 1.9261
    Cell Dimensions: a: 13.56 Å
    b: 5.82 Å
    c: 11.21 Å
    Z: 2
    b: 100.75°
    V: 869.16 Å3
    DenCalc: 4.61
    H-M Symbol: 2/m
    Space Group: C2/m
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 2.71 Å
    (1): 3.14 Å
    (1): 3.17 Å
    		Chevkinite-(Ce)
    Crystal
    Habit:
  • Acicular
  • Massive
    		•   
    Cleavage: None  
    Fracture: Brittle - Conchoidal  
    Moh's
        Hardness:    		 5 - 5.5  
    Density: 4.5 grams/cm3
    Color: Brown-black  
    Streak: Black  
    Luster:
  • Earthy
  • Vitreous
    		•   
    Diaphaneity: Translucent to subtranslucent to opaque  
    Pleochroism:
    (x): Nearly colorless
    (y:) Pale reddish brown
    (z:) Dark reddish brown
    		 
    Ultra Violet
        Fluorescence:    		 Non-fluorescent  
    Magnetism: Non-magnetic  
    Occurance:
  • Secondary mineral in titanium and cerium bearing rocks
  • As an accessory mineral in some granites
    		•   
    Associated
        Minerals:    		 Actinolite, Aegirine, Albite, 'Albite-Anorthite Series', Allanite-(Ce), Analcime, Anatase, Ancylite-(Ce), Andradite, Arfvedsonite, Astrophyllite, Augite, Barite, Bastnäsite-(Ce), Biotite, Calcite, Cancrinite, Carbonate-fluorapatite, Clinochlore, Epidote, Eudialyte, Fayalite, Fluorapatite, Fluorite, Galena, Gibbsite, Goethite, Grossular, Gypsum, Hastingsite, Hematite, 'Hornblende', Ilmenite, Loparite-(Ce), Magnetite, Microcline, Molybdenite, Monazite-(Ce), 'Mosandrite', Muscovite, Nepheline, Orthoclase, Perovskite, Phlogopite, Polylithionite, Prehnite, Pyrite, Pyrochlore, Pyrrhotite, Quartz, Rutile, Siderite, Sodalite, Sphalerite, Thomsonite, Thorianite, Thorite, Titanite, Vesuvianite, Xenotime-(Y), Zircon

    Mineral   -   > 50% of sites
    Mineral   -   > 25% of sites
    Mineral   -   > 15% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with
    Chevkinite-(Ce)
    Localities:

    Rare

    Chevkinite-(Ce) Localities
    Notes:

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

    Chevkinite-(Ce) Images

    Arondu, Harmosh Range, Baltistan, Pakistan

    Specimen Notes

    Occurrence -  

     

    Crystals -  

     

    Appearence -  

    Diaphaniety -

    Luster -

     

      -  

     

    Specimen Physical Properties
    Size   cm   cm   cm
    Weight: x grams    
    g-Radiation Level:   cmp   msieverts background: 20 cpm
           
     

     
     

    (02)
    Image courtesy
    Dave Barthelmy
    Miass, Central Ural Mountains, Russia