Melanocerite-(Ce)

 IMA-GP
Thorium 54.2.5.3
(Dana Classification Number)
(Images) 8/B.33-10
(Strunz ID)

Property Data Remarks
Named for: The Greek word for 'black', and its Cerium content
Alternate
    Name(s):
  		•  
    Mineral Class:
    Silicates
      Nesosilicates, with anions unfamiliar to tetraheders, with Beryllium and Boron
        Melanocerite-(Ce) - Tritomite-(Ce) series
    		 
    Chemical
        Formula:    		 (Ce,Th,Ca)5(Si,B)3O12(OH,F) · nH2O  
    Chemical
        Composition:
    Boron: (B) 1.20%
    Calcium: (Ca) 4.88%
    Cerium: (Ce) 46.55%
    Fluorine: (F) 1.05%
    Hydrogen: (H) 0.28%
    Lanthanum: (La) 10.77%
    Oxygen: (O) 23.92%
    Silicon: (Si) 6.22%
    Thorium: (Th) 5.14%
    		by weight
    Molecular
        Weight:    		 903.06 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    2.302 × 1003 6.22 × 10-08 0.03 3.21

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Trigonal
    Axial Ratios: a: 1
    c: 0.73582
    Cell Dimensions: a: 9.35 Å
    c: 6.88 Å
    Z: 2
    V: 520.89 Å3
    DenCalc: 5.76
    H-M Symbol:  
    Space Group: unknown (HEX-R)
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 2.81 Å
    (0.4): 1.84 Å
    (0.4): 3.44 Å
    		 
    Habit:
  • Tabular
  • Metamict
    		•   
    Cleavage: None  
    Fracture: Brittle - Conchoidal  
    Moh's
        Hardness:    		 5 - 6  
    Density: 4.13 grams/cm3
    Color: Brown, black  
    Streak: Light brown  
    Luster: Resinous  
    Diaphaneity: Subtransparent to Opaque  
    Dichroism:
    (e):  
    (w:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
    • Alkalic rocks and their cogenetic pegmatites
    • In metamorphosed alkalic rocks
    		  
    Associated
        Minerals:

    Calcite, Chalcopyrite, Fluorite, Hematite, Magnetite, Molybdenite, Pyrite, Pyrrhotite, Titanite

    Mineral   -   > 75% of sites
    Minerals   -   Uranium & Thorium
    mineral links

    		These are minerals known to be found with Melanocerite-(Ce)
    Locations:

    Extremely rare

    Melanocerite-(Ce) Locations
    Notes:

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

    Crystals may be metamic.

    Melanocerite-(Ce) Images

    Specimen Top
    (001a) (001b) (001c) (001d)
    (001e)
     
    Cardiff Uranium mine, Wilberforce, Monmouth Township, Haliburton Co., Ontario, Canada

    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