Coconinoite

 IMA-A 1965-003
Uranium 43.5.5.1
(Dana Classification Number)
(Images) 7/E.06-20
(Strunz ID)

Property Data Remarks
Named for: Coconino Co., Arizona, USA, its type locality
Alternate
    Name(s):
  		•  
    Mineral Class:
    Phosphates, Arsenates and Vanadates
      Uranylphosphates and uranylvanadates with
    [UO2]2+ - [PO4 | AsO4]3- and
    [UO2]2+ - [V2O8]6-
        Vochtenite - Xiangjianite series
    		 
    Chemical
        Formula:    		 Fe+32Al2(UO2)2(PO4)4(SO4)(OH)2 · 20H2O  
    Chemical
        Composition:
    Aluminum: (Al) 3.74%
    Hydrogen: (H) 2.65%
    Iron: (Fe) 7.74%
    Oxygen: (O) 44.32%
    Phosphorus: (P) 8.58%
    Uranium: (U) 32.97%
    		by weight
    Molecular
        Weight:    		 1443.89 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    5.5336 × 1004 1.50 × 10-06 0.82 8.19

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Monoclinic, or possibly Orthorhombic
    (Monoclinic form supported by the extinction lines from x-ray diffraction studies)
    Axial Ratios: a: 0.9637
    b: 1
    c: 1.7733
    Cell Dimensions: a: 12.5 Å
    b: 12.97 Å
    c: 23 Å
    Z: 4
    b: 106.6°
    V: 3,573.47 Å3
    DenCalc: 2.68
    H-M Symbol:  
    Space Group: C2/c, Cc
    X-Ray Diffraction:
      By Intensity ( I/Io )    		 (1): 11.1 Å
    (0.8): 3.29 Å
    (0.8): 3.74 Å
    		 
    Habit:
    Microscopic crystals
  • Micacious - platy
  • Lath micro-crystals(tabular - rectangular - in shape)
  • Crusts
  • Earthy masses
  • foliated and scaly aggregates
    		•   
    Cleavage:
    [001]  
    [010]  
    [100]  
    		 
    Fracture:    
    Moh's
        Hardness:    		 1 - 2  
    Density: 2.7 - 2.9 grams/cm3
    Color: Various shades of pale Yellow  
    Streak: White to pale yellow  
    Luster: Vitreous or waxy to dull or earthy  
    Diaphaneity: Crystals are translucent  
    Pleochroism:
    (x): Colorless
    (y:) Pale yellow
    (z:) Pale yellow
    		 
    Ultra Violet
        Fluorescence:
    Long Wave: Some specimens are fluorescent.
    Short Wave: Some specimens are fluorescent.
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • in an oxidized zone of sandstone uranium deposits
    		•   
    Associated
        Minerals:

    Vochtenite, Xiangjiangite

    Often found covered with gypsum. Also associated with jarosite, limonite, petrified wood and coalized wood, clays, and with uranium ores. It was found on quartz sandstone.

    		  
    Localities:

    Very rare

    Coconinoite Localities
    Notes:

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

    Extremely unusual mineral chemistry, having hydroxyl, phosphate and sulfate groups.

    Discovered by A.F. Trites, Jr. of the U.S. Geological Survey, in 1953 while conducting a study of the Uranium deposits in the White Canyon area of southern Utah.

    Coconinoite Images

    Specimen
    (001a) (001b) (001c) (001d)
    Jomas mine, White Canyon, San Juan Co., Utah, USA

    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