Yttrialite-(Y)

Yttrialite or Yttrialite-(Y) is a rare yttrium thorium sorosilicate mineral with formula: (Y,Th)2Si2O7. It forms green to orange yellow masses with conchoidal fracture. It crystallizes in the monoclinic-prismatic crystal system. It has a Mohs hardness of 5 to 5.5 and a specific gravity of 4.58. It is highly radioactive due to the thorium content.
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General Information:
 Chemical Formula:
(Y,Th)2Si2O7
 Empirical Formula:
Y1.5HTh0.5Si2O7
 Environment:
Associated with gadolinite.
 IMA Status:
Approved IMA 1987
 Locality:
Llano Co., Texas, USA.
Physical Properties:
 Cleavage:
None
 Color:
green or orangish yellow.
 Density:
4.58
 Habits:
Massive - Uniformly indistinguishable crystals forming large masses., ,
 Hardness:
5-5.5 - Apatite-Knife Blade
 Luminescence:
Non-fluorescent.
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