General Information:
Chemical Formula:
NaLiAl2(Al2Si2)O10(OH)2
Composition:
(Molecular Weight = 388.04 gm)
Sodium 5.92 % Na
Lithium 1.79 % Li
Aluminum 27.81 % Al
Silicon 14.48 % Si
Hydrogen 0.52 % H
Oxygen 49.48 % O
Empirical Formula:
NaLiAl4Si2O10OH2
Environment:
Peri-aluminous metamorphic rocks. Ca analog of muscovite.
IMA Status:
Approved IMA
Locality:
Gumuchdahg, Ephesus, near Izmir, Turkey.
Name Origin:
Named after the locality.
Physical Properties:
Cleavage:
[001] Perfect
Color:
brownish pink, pearl gray, or pale green.
Density:
2.984
Diaphaniety:
Translucent
Hardness:
3.5-4.5
Luster:
Vitreous - Pearly
Streak:
white
More details...