Tyuyamunite

 IMA-GP
Uranium 40.2a.26.1
(Dana Classification Number)
(No Images) 7/E.11-80
(Strunz ID)
Unless sealed in glass, all specimens should be considered to have become Metatyuyamunite within a few months of being exposed to ambient air.

Property Data Remarks
Named for: Tyuya Muyun hill (Tuja Mujun) (a northern spur of the Alai Mountains), Ferghana, Uzbekistan, its type locality
Alternate
    Name(s):
  • Calciocarnotite
    		•   
    Mineral Class:
    Phosphates, Arsenates and Vanadates
      Uranylphosphates and uranylvanadates with:
    [UO2]2+ - [PO4 | AsO4]3- and [UO2]2+ - [V2O8]6-,
    uranyl-group vanadates with [UO2]2+ - [V2O8]6-
        Tyuyamunite series
    		 
    Chemical
        Formula:    		 Ca(UO2)2(VO4)2 · 5-8H2O  
    Chemical
        Composition:
    Calcium: (Ca) 4.37%
    Hydrogen: (H) 1.32%
    Oxygen: (O) 31.37%
    Uranium: (U) 51.85%
    Vanadium: (V) 11.10%
    		by weight
    Molecular
        Weight:    		 918.10 daltons (amu)
    Specific
        Radioactivity:

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

    Specific Activity Dose Rate
    Becquerels Curies milliRems/hour microSieverts/hour
    9.2816 × 1004 2.51 × 10-06 1.29 128.52

    Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
    Crystalography:
    System: Orthorhombic - Dipyramidal
    Axial Ratios: a:b:c = 1.2392:1:2.4401
    Cell Dimensions: a = 10.36, b = 8.36, c = 20.4, Z = 4; V = 1,766.84 Den(Calc) = 3.45
    H-M Symbol: 2/m 2/m 2/m
    Space Group: Pnan
    X Ray Diffraction: By Intensity(I/Io): 10.18(1) 5.02(0.9) 3.2(0.5)
    		Tyuyamunite
    Crystal
    Habit:
  • Crusts.
  • Foliated.
  • Earthy.
  • Scaly.
  • Platy (micatious).
  		•   
    Cleavage:
    [001] Perfect
    [010] Distinct
    [100] Distinct
    		 
    Fracture: Uneven  
    Moh's
        Hardness:    		 1.5 - 2  
    Density: 3.3 - 3.8 - 4.3

    (higher density with lower water content)    		 grams/cm3
    Color: Yellow  
    Streak: Light yellow to Greenish yellow  
    Luster: Adamantine - Pearly  
    Diaphaneity: Translucent to Opaque  
    Pleochroism:
    (x): None.
    (y:) None.
    (z:) None.
    		 
    Ultra Violet
        Fluorescence:
    Long Wave: Some specimens are weakly fluorescent, yellow to yellow-green.
    Short Wave: Some specimens are weakly fluorescent, yellow to yellow-green.
    		 
    Magnetism: Non-magnetic  
    Occurance:
  • Sandstones.
  • Petrified trees and other fossils.
    		•   
    Associated
        Minerals:

    Autunite, Barite, Calcite, Carnotite, Coffinite, Huemulite, Malachite, Metatyuyamunite, Pyrite, Quartz, Schröckingerite, Uraninite, Uranophane

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

    		These are minerals known to be found with Tyuyamunite
    Locations:

    Relatively common Uranium mineral

    Tyuyamunite Locations
    Notes:

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

    Crystal structure is the single best way to differentiate it from Carnotite.