Zykaite

General Information:
 Chemical Formula:
Fe+++4(AsO4)3(SO4)(OH)·15(H2O)
 Composition:
(Molecular Weight = 1,023.45 gm)
Iron 21.83 % Fe
Arsenic 21.96 % As
Hydrogen 3.05 % H 
Sulfur 3.13 % S 
Oxygen 50.03 % O 
 Empirical Formula:
Fe3+4(AsO4)3(SO4)(OH)·15(H2O)
 IMA Status:
Approved IMA 1978
 Locality:
Kank, near Kutna Hora, Czech Republic.
 Name Origin:
Named for Vaclav Zyka (1926-), Czech geochemist.
Physical Properties:
 Color:
greenish white or gray white.
 Density:
2.5
 Diaphaniety:
Translucent
 Habits:
Nodular - Tuberose forms having irregular protuberances over the surface., ,
 Hardness:
2 - Gypsum
 Luster:
Earthy (Dull)
 Streak:
white
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