Weberite

General Information:
 Chemical Formula:
Na2MgAlF7
 Composition:
(Molecular Weight = 230.25 gm)
Sodium 19.97 % Na
Magnesium 10.56 % Mg
Aluminum 11.72 % Al
Fluorine 57.76 % F 
 Empirical Formula:
Na2MgAlF7
 Environment:
With cryolite and other fluorides.
 Locality:
Ivigtut, Greenland.
 Name Origin:
Named for Theobald C. F. Weber (1823-1886), one of the founders of the cryolite industry in Denmark.
Physical Properties:
 Cleavage:
[101] Poor, [010] Indistinct
 Color:
greenish, gray, grayish white, or white.
 Density:
2.96
 Diaphaniety:
Translucent
 Habits:
Anhedral Grains - Granular minerals without the expression of crystal shapes, Massive - Uniformly indistinguishable crystals forming large masses.,
 Hardness:
3.5 - Copper Penny
 Luster:
Vitreous (Glassy)
 Streak:
white
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