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Ursilite

Formula:
(Mg,Ca)
 
4
(UO
 
2
)
 
4
(Si
 
2
O
 
5
)
 
5.5
(OH)
 
5
·13H
 
2
O
System:OrthorhombicColour:Light yellow, ...
Lustre:Vitreous, SilkyHardness:2 - 3
Name:The name reflects the URANium and SILicon content
This page provides mineralogical data about Ursilite.

Classification of Ursilite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:8/B.37-10
Nickel-Strunz 10th (pending) edition ID:9.AK.35

9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates
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Type Occurrence of Ursilite

Type Locality:Oktyabr'skoye U Deposit, Kyzyltyube-Sai, Khodzhent (Leninabad), Viloyati Sogd (Viloyati Sughd; Viloyati Khodzhent; Viloyati Leninabad), Tajikistan

Occurrences of Ursilite

Geological Setting:Uranium deposit

Physical Properties of Ursilite

Lustre:Vitreous, Silky
Colour:Light yellow, straw-yellow
Hardness (Mohs):2 - 3
Density (calculated):3.25 g/cm3

Crystallography of Ursilite

Crystal System:Orthorhombic
Cell Parameters:a = 11.60Å, b = 14.68Å, c = 12.83Å
Ratio:a:b:c = 0.79 : 1 : 0.874
Unit Cell Volume:V 2,184.80 ų (Calculated from Unit Cell)
Z:6
Morphology:Needlelike crystals (only visible in SEM)

Optical Data of Ursilite

Type:Biaxial (-)
RI values: nα = 1.570 nγ = 1.584
Maximum Birefringence:δ = 0.014

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Moderate

Chemical Properties of Ursilite

Formula:
(Mg,Ca)
 
4
(UO
 
2
)
 
4
(Si
 
2
O
 
5
)
 
5.5
(OH)
 
5
·13H
 
2
O
Essential elements:H, Mg, O, Si, U
All elements listed in formula:Ca, H, Mg, O, Si, U

Relationship of Ursilite to other Species

Related Minerals - Nickel-Strunz Grouping):

- +
9.AK.05Soddyite
(UO
 
2
)
 
2
SiO
 
4
·2H
 
2
O
9.AK.10Cuprosklodowskite
Cu(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
 · 6H
 
2
O
9.AK.10Oursinite
(Co,Mg)(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
 · 6H
 
2
O
9.AK.10Sklodowskite
Mg(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
 · 5H
 
2
O
9.AK.15Boltwoodite
(K,Na)(UO
 
2
)[HSiO
 
4
] · 0.5H
 
2
O
9.AK.15Kasolite
Pb(UO
 
2
)[SiO
 
4
] · H
 
2
O
9.AK.15Natroboltwoodite
(H
 
3
O)(Na,K)UO
 
2
SiO
 
4
·H
 
2
O
9.AK.15Uranophane
Ca(UO
 
2
)
 
2
[HSiO
 
4
]
 
2
 · 5H
 
2
O
9.AK.15Beta-Uranophane
9.AK.20Swamboite
UH
 
6
(UO
 
2
)
 
6
(SiO
 
4
)
 
6
·30H
 
2
O
9.AK.25Haiweeite
Ca(UO
 
2
)
 
2
[Si
 
5
O
 
12
(OH)
 
2
]·4.5H
 
2
O
9.AK.25Metahaiweeite
Ca(UO
 
2
)
 
2
Si
 
6
O
 
15
·nH
 
2
O
9.AK.25Ranquilite
9.AK.30Weeksite
K
 
2
(UO
 
2
)
 
2
(Si
 
2
O
 
5
)
 
3
·4H
 
2
O
9.AK.30Coutinhoite
Th
 
x
Ba
 
(1-2x)
(UO
 
2
)
 
2
Si
 
5
O
 
13
·(H
 
2
O)
 
1+y
 (0 < x < 0.5 and 0 < y < (2+x))
9.AK.35Magnioursilite
Mg
 
4
(UO
 
2
)
 
4
(Si
 
2
O
 
5
)
 
5
(OH)
 
6
·20H
 
2
O
9.AK.35Calcioursilite
Ca
 
4
(UO
 
2
)
 
4
(Si
 
2
O
 
5
)
 
5
(OH)
 
6
·15H
 
2
O
9.AK.40Uranosilite
UO
 
3
 · 7SiO
 
2

Other Names for Ursilite

Synonyms:
Mg-Ursilite
Other Languages:
German:Mg-Ursilit
Ursilit
Spanish:Ursilita
Varieties:
Calcium-ursiliteMagnioursilite

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Ursilite

Reference List:Zapiski Vserossiyskogo Mineralogicheskogo Obshchestva (1977): 106: 553-564.

Internet Links for Ursilite

Search Engines:
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    • External Links:
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  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Ursilite in the Natural History Museum (London) online catalogue
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    Localities for Ursilite

    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Tajikistan
     
    • Region of Republican Subordination
      • Tien Shan Mts
        • Alai (Alayskiy) Range
    		http://www.koeln.netsurf.de/~w.steffens/dara.htm
    • Viloyati Sogd (Viloyati Sughd; Viloyati Khodzhent; Viloyati Leninabad)
      • Khodzhent (Leninabad)
        • Kyzyltyube-Sai
    		Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
    Mineral and/or Locality
    Google
     
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    Copyright © Jolyon Ralph and Ida Chau 1993-2009. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. If you would like to add information to improve the quality of our database, then click here to register. Current server date and time: 10th Nov 2009 13:25:26