Sauconite

Sauconite is a complex phyllosilicate mineral of the smectite clay group, formula Na0.3Zn3(SiAl)4O10(OH)2·4H2O. It forms soft earthy bluish white to red-brown monoclinic crystals typically massive to micaceous in habit. It has a Mohs hardness of 1 to 2 and a specific gravity of 2.45. Optically it is biaxial positive with refractive index values of nα = 1.550 - 1.580, nβ = 1.590 - 1.620 and nγ = 1.590 - 1.620.
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General Information:
 Chemical Formula:
Na0,3Zn3(Si,Al)4O10(OH)2·4(H2O)
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
bluish white or reddish brown.
 Density:
2.45
 Diaphaniety:
Translucent to Opaque
 Hardness:
1-2 - Between Talc and Gypsum
 Luster:
Earthy (Dull)
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B: (Kimia) saukonit
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