Gearksutite

General Information:
 Chemical Formula:
CaAl(OH,F)5·(H2O)
 Composition:
(Molecular Weight = 178.08 gm)
Calcium 22.51 % Ca
Aluminum 15.15 % Al
Hydrogen 1.70 % H 
Oxygen 17.97 % O 
Fluorine 42.67 % F 
 Empirical Formula:
CaAl(OH)F4·(H2O)
 Environment:
Alteration product of cryolite.
 IMA Status:
Approved IMA 1959
 Locality:
Greenland and Ural Mountains, Russia.
 Name Origin:
Named from the Greek "Ge", for earth because it is usually earthy and arksutite, from the locality near Arksut fjord.
Physical Properties:
 Cleavage:
None
 Color:
white.
 Density:
2.75
 Diaphaniety:
Transparent to subtranslucent
 Habits:
Acicular - Occurs as needle-like crystals., Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).,
 Hardness:
2 - Gypsum
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous - Dull
 Streak:
white
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