General Information:
Chemical Formula:
(Li,Ca0.5,Na)0.72(LI,Al,Mg)2.66(Si,Al)4O10(OH,F)2·2(H2O)
Composition:
(Molecular Weight = 397.20 gm)
Sodium 0.58 % Na
Lithium 1.75 % Li
Calcium 5.05 % Ca
Magnesium 3.06 % Mg
Aluminum 10.19 % Al
Silicon 21.21 % Si
Hydrogen 1.40 % H
Oxygen 54.38 % O
Fluorine 2.39 % F
Empirical Formula:
LiCa0.5Na0.1Al1.5Mg0.5Si3O10(OH)1.5F0.5·2(H2O)
IMA Status:
Approved IMA 1975
Locality:
Foote Quarry, Kings Mountain, Cleveland County, North Carolina, USA.
Name Origin:
Named for Ada Swineford (1917-1993), clay mineralogist and professor of geology at Western Washington State College, Bellingham, Washinton, USA.
Physical Properties:
Cleavage:
[001] Perfect
Color:
greenish gray or light olive green.
Density:
2.3 - 2.8, Average = 2.54
Diaphaniety:
Translucent to Opaque
Habits:
Aggregates - Made of numerous individual crystals or clusters., ,
Hardness:
1 - Talc
Luster:
Earthy (Dull)
Streak:
white
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