Terskite

General Information:
 Chemical Formula:
Na4Zr(H4Si6O18)
 Composition:
(Molecular Weight = 643.72 gm)
Sodium 14.29 % Na
Zirconium 14.17 % Zr
Silicon 26.18 % Si
Hydrogen 0.63 % H 
Oxygen 44.74 % O 
 Empirical Formula:
Na4ZrH4Si6O18
Physical Properties:
 Color:
white or light lilac.
 Density:
2.71
 Hardness:
5 - Apatite
 Luminescence:
Fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
More details...