Iraqite-(La)

 IMA-A 1973-041
Thorium 63.1.1.2
(Dana Classification Number)
(No Images) 8/E.10-20
(Strunz ID)

Property Data Remarks
Named for: its country of discovery, Iraq, and its Lanthanum content
Alternate
    Name(s):
  • Desourdyite
  • Ekanite
    		•  Ekanite is a chemically related mineral
    Mineral Class:
    Silicates
      Cyclosilicates, double quadruplet rings [Si8O20]-8
        Ekanite - Steacyite series
    		 
    Chemical
        Formula:    		 K(La,Ce,Th)2(Ca,Na)4(Si,Al)16O40 Chemically related to Ekanite
    Chemical
        Composition:
    Aluminum: (Al) 0.50%
    Calcium: (Ca) 8.58%
    Cerium: (Ce) 6.00%
    Lanthanum: (La) 5.95%
    Oxygen: (O) 39.15%
    Potassium: (P) 2.63%
    Silicon: (Si) 26.98%
    Sodium: (Na) 0.28%
    Thorium: (Th) 9.94%
    		by weight
    Molecular
        Weight:    		 1,634.63 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    4.452 × 1003 1.20 × 10-07 0.07 0.67

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Tetragonal - Ditetragonal Dipyramidal
    Axial Ratios: a: 1
    c: 1.94086
    Cell Dimensions: a: 7.61 Å
    c: 14.77 Å
    Z: 1
    V: 855.36 Å3
    DenCalc: 3.17
    H-M Symbol: 4/m 2/m 2/m
    Space Group: P4/mcc
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 2.64 Å
    (1): 3.31 Å
    (1): 5.28 Å
    		 
    Habit:
  • Anhedral Grains
  • Massive
    		•   
    Cleavage:
    [???] Good
    [???] Good
    [???] Poor
    		 
    Fracture: Uneven  
    Moh's
        Hardness:    		 4.5  
    Density: 3.27 grams/cm3
    Color: Pale greenish yellow  
    Streak: White  
    Luster: Earthy  
    Diaphaneity: Transparent to Translucent  
    Pleochroism:
    (x):  
    (y:)  
    (z:)  
    		 
    Ultra Violet
        Fluorescence:
    Long Wave:  
    Short Wave:  
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • In granite in contact with dolomitic marble containing olivine and diopside
    		•   
    Associated
        Minerals:

    Diopside, 'Olivine'

    		 No other minerals listed occurring with Iraqite-(La)
    Localities:

    Extremely rare

    Iraqite-(La) Localities
    Notes:

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

    Crystals are probably metamic.