Redingtonite

General Information:
 Chemical Formula:
(Fe++,Mg,Ni)(Cr,Al)2(SO4)4·22(H2O)
 Composition:
(Molecular Weight = 918.74 gm)
Magnesium 0.79 % Mg
Aluminum 1.47 % Al
Chromium 8.49 % Cr
Iron 3.65 % Fe
Nickel 0.64 % Ni
Hydrogen 4.83 % H 
Sulfur 13.96 % S 
Oxygen 66.17 % O 
 Empirical Formula:
Fe2+0.6Mg0.3Ni0.1Cr1.5Al0.5(SO4)4·22(H2O)
 Locality:
Redington mine, Knoxville, Napa Co., California.
 Name Origin:
Named after it's locality.
Physical Properties:
 Color:
white, light violet, or light purple.
 Density:
1.761
 Diaphaniety:
Transparent
 Habits:
Fibrous - Crystals made up of fibers., ,
 Hardness:
2 - Gypsum
 Luminescence:
Non-fluorescent.
 Luster:
Silky
 Streak:
white
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