Barylite

General Information:
 Chemical Formula:
BaBe2Si2O7
 Composition:
(Molecular Weight = 323.52 gm)
Barium 42.45 % Ba
Beryllium 5.57 % Be
Silicon 17.36 % Si
Oxygen 34.62 % O 
 Empirical Formula:
BaBe2(Si2O7)
 Environment:
Alkalic pegmatites and miarolitic cavities. Also in nephelene syenites and other alkalic intrusions.
 Locality:
Langbanshyttan, Vermland, Sweden.
 Name Origin:
Named from the Greek for "heavy", in allusion to its high specific gravity.
Physical Properties:
 Cleavage:
[001] Perfect, [100] Perfect
 Color:
bluish, colorless, or white.
 Density:
4.02 - 4.07, Average = 4.04
 Diaphaniety:
Transparent
 Habits:
Platy - Sheet forms (e.g. micas)., ,
 Hardness:
6-7 - Orthoclase-Quartz
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
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