General Information:
Chemical Formula:
NaMg3Al6(BO3)3Si6O18(OH)4
Composition:
(Molecular Weight = 1,135.17 gm)
Sodium 2.03 % Na
Magnesium 6.42 % Mg
Aluminum 14.26 % Al
Silicon 14.84 % Si
Boron 5.71 % B
Hydrogen 0.36 % H
Oxygen 56.38 % O
Empirical Formula:
NaMg3Al6(BO3)3Si6O18(OH)4
Environment:
Metasomatically altered magnesian or dolomitic limestones in contact-metamorphic aureoles.
Locality:
Drava River, Austria.
Name Origin:
After its locality.
Physical Properties:
Cleavage:
[???] Indistinct
Color:
black, green, red, blue, or white.
Density:
2.98 - 3.2, Average = 3.09
Diaphaniety:
Transparent to translucent to opaque
Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Columnar - Forms columns, Divergent - Crystals radiate from a center without producing stellar forms.
Hardness:
7-7.5
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Resinous
Streak:
colorless
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