Gagarinite-(Y)

General Information:
 Chemical Formula:
NaCaY(F,Cl)6
 Composition:
(Molecular Weight = 450.18 gm)
Sodium 5.11 % Na
Calcium 8.90 % Ca
Yttrium 19.75 % Y 
Chlorine 47.25 % Cl
Fluorine 18.99 % F 
 Empirical Formula:
NaCaYF4.5Cl6
 IMA Status:
Approved IMA 1987
Physical Properties:
 Cleavage:
[???] Good
 Color:
yellow, cream white, light brown, or pink.
 Density:
4.21
 Diaphaniety:
Transparent
 Hardness:
4.5 - Between Fluorite and Apatite
 Luster:
Vitreous - Dull
 Streak:
white
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