Gaultite

General Information:
 Chemical Formula:
Na4Zn2Si7O18·5(H2O)
 Composition:
(Molecular Weight = 797.40 gm)
Sodium 11.53 % Na
Zinc 16.40 % Zn
Silicon 24.65 % Si
Hydrogen 1.26 % H 
Oxygen 46.15 % O 
 Empirical Formula:
Na4Zn2Si7O18·5(H2O)
 Environment:
In a cavity in a sodalite syenite xenolith near a contact of hornfels and nepheline-sodalite syenite.
 IMA Status:
Approved IMA
 Locality:
Poudrette Quarry, Mont Saint-Hilaire, Rouville County, Quebec, Canada.
 Name Origin:
Named after Robert Allan Gault (1943- ) of the Canadian Museum of Nature.
Physical Properties:
 Cleavage:
[101] Perfect, [010] Perfect, [021] Poor
 Color:
colorless or pale mauve.
 Density:
2.52
 Diaphaniety:
Transparent
 Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., ,
 Hardness:
6 - Orthoclase
 Luminescence:
Fluorescent, Short UV=bright green.
 Luster:
Vitreous (Glassy)
 Streak:
white
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