General Information:
Chemical Formula:
Na3Ca(Al3Si3O12)S
Composition:
(Molecular Weight = 498.31 gm)
Sodium 13.84 % Na
Calcium 8.04 % Ca
Aluminum 16.24 % Al
Silicon 16.91 % Si
Sulfur 6.43 % S
Oxygen 38.53 % O
Empirical Formula:
Na3CaAl3Si3O12S
Locality:
District of Badakhshan, Afghanistan.
Name Origin:
From the Persian lazward - "blue."
Physical Properties:
Cleavage:
[110] Imperfect
Color:
blue, azure blue, violet blue, or greenish blue.
Density:
2.38 - 2.42, Average = 2.4
Diaphaniety:
Translucent
Habits:
Massive - Granular - Common texture observed in granite and other igneous rock., ,
Hardness:
5.5 - Knife Blade
Luminescence:
Fluorescent.
Luster:
Vitreous - Dull
Streak:
light blue
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