Cheralite-(Ce)

 IMA-GP
Thorium 38.4.3.3
(Dana Classification Number)
(Images) 7/A.15-40
(Strunz ID)

Property Data Remarks
Named for: Chera (Kerala), an ancient Dravidian kingdom predating Travancor (now Kerala State), India, and its Cerium content.
Alternate
    Name(s):
  • Cheralite
  
Mineral Class:
Phosphates, Arsenates and Vanadates
  Waterfree phosphates [PO4]3-
without unfamiliar anions, cations of very big size: Ca, Na
    Monazite group
 
Chemical
    Formula:		 (Ce,Ca,Th)(P,Si)O4  
Chemical
    Composition:
Calcium: (Ca)   5.01%
Cerium: (Ce)   11.68%
Lanthanum: (La)   5.79%
Neodymium: (Nd)   6.01%
Oxygen: (O)   26.68%
Phosphorus: (P)   11.62%
Silicon: (Si)   1.17%
Thorium: (Th)   29.02%
REE2O3
    Lanthanum:
    Cerium:
    Praesyodymium:
    Neodymium:
    Samarium:		  
(La)
(Ce)
(Pr)
(Nd)
(Sm)		 |
|
|
|
|
|		 3.00%
by weight
Molecular
    Weight:		 239.85 daltons (amu)
Specific
    Radioactivity:

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

Specific Activity Dose Rate
Becquerels Curies  milliRems 
hour		  microSieverts 
hour
1.3002 × 1004 3.51 × 10-07 0.18 1.80

Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
Crystalography:
System: Monoclinic - Prismatic
Axial Ratios: a: 0.9706
b: 1
c: 0.9297
Cell Dimensions: a: 6.717 Å
b: 6.92 Å
c: 6.434 Å
Z: 4
b: 103.833°
V: 290.39 Å3
DenCalc: 5.49
H-M Symbol: 2/m
Space Group: P21/n
X-Ray Diffraction:
  By Intensity ( I/Io )		 (1): 3.07 Å
(0.9): 2.86 Å
(0.9): 3.26 Å
 
Habit:
  • Anhedral Grains
  • Massive
    		•   
    Cleavage:
    [001] Parting
    [010] Distinct
    [100] Poor
    		 
    Fracture: Brittle - Uneven  
    Moh's
        Hardness:    		 5  
    Density: 5.3 grams/cm3
    Color: Brown, Light green to Dark green, Colorless  
    Streak: White  
    Luster: Vitreous - Resinous  
    Diaphaniety: Transparent  
    Pleochroism:
    (x): Green
    (y:) Green
    (z:) Yellowish green
    		 
    Ultra Violet
        Fluorescence:
    Long Wave: None
    Short Wave: Light Green - light green colored areas
    (extremely weak - 12 Watt U.V. and dark adapted eyes)
    None in dark colored areas
    		(One specimen Examined)
    Magnetism: Non-magnetic  
    Occurance:
  • Disseminated in a kaolinitized pegmatite dike
    		•   
    Associated
        Minerals:

    Albite, Almandine, Anatase, Anhydrite, Ankerite, Barite, Bastnäsite-(Ce), Bavenite, Bertrandite, Beryl var: Aquamarine, Biotite, Boulangerite, Brookite, Calaverite, Calcite var: Manganoan Calcite, Ceriopyrochlore-(Ce), 'Chlorite', 'Columbite-Tantalite', Cookeite, Euclase, Eudialyte var: Eucolite, Fluorite, Galena, Gold, Grossular, Hematite, Hisingerite, Huttonite, Ilmenite, Ixiolite, Jamesonite, Lepidocrocite, Liandratite, Microcline, Microlite, 'Monazite', Muscovite, Opal var: Hyalite, 'Parisite', Phenakite, Polycrase-(Y), Psilomelane', Quartz, Rutile var: Ilmenorutile, Sanidine, Siderite, Sphalerite, Stibiconite, Stilpnomelane, 'Synchysite', 'Tourmaline Group', Uranpyrochlore, Xenotime-(Y)

    Minerals   -   Uranium & Thorium
    mineral links

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

    Rare

    Cheralite-(Ce) Localities
    Notes:

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

    Crystals are probably metamic.

    Cheralite-(Ce) Images

    Specimen #1
    (001aa) (001a) (001b) (001ab)
    (001c) (001d) (001e)

     
    Uranium King Mine (Platt Pegmatite Mine; Platt Mine), Trent Creek, Encampment Copper District, Sierra Madre Mts., Carbon Co., Wyoming, U.S.A.

    Specimen Notes

    Occurrence - Nearly the entire specimen is Cheralite-(Ce). There is almost no trace of the matrix in which it grew.

    Crystals - The Cheralite-(Ce) is massive, so no crystal form can be seen. However, most of the specimen is a part of one crystal.

    The three clevage planes can be seen. The plane that was photographed in (001a) - (001e) is very well defined, but not quite perfect, much like slate. Unlike slate, it does not appear to break easily along the near perfect plane. The poorer cleavage planes appear to break much more easily. The other two planes, best seen in image (001b), are good to poor in clevage, being very uneven.

    Appearence - The specimen shows all of the typical colors of Cheralite-(Ce). The more weathered parts of the specimen show the lighter colorations.

    Diaphaniety - The specimen is opaque, showing no sign of being even slightly transluscent.

    Luster - The luster is generally earthy with a very flat surface, very much like a high quality slate. Under the microscope, some areas, such as those shown in (001b) and (001d), are almost vitreous.

    Fluorescence - The light green mineral, such as seen in the lower left quarter of image (001d), have an extremely weak fluorescence of a pale green color. This fluorescence is so weak that the room must be in total darkness, and the eyes dark adaptedm and is just noticable even then.

    The mineral that isn't this light green color, including that of image (001b), does not produce even the slightest fluorescence.

    Specimen Physical Properties
    Weight: 28.57 grams    
    Size: 4.8 cm 2.5 cm 1.0 cm
    g-Radiation Level: 204 cmp 20.4 msieverts background: 23.6 cpm