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
More details...