General Information:
Chemical Formula:
Fe++Al2(SO4)4·22(H2O)
Composition:
(Molecular Weight = 890.40 gm)
Aluminum 6.06 % Al
Iron 6.27 % Fe
Hydrogen 4.98 % H
Sulfur 14.41 % S
Oxygen 68.28 % O
Empirical Formula:
Fe2+Al2(SO4)4·22(H2O)
Name Origin:
From the Latin, halotrichum ="hairy salt."
Physical Properties:
Cleavage:
[010] Indistinct
Color:
colorless, green, gray white, yellow, or white.
Density:
1.78 - 1.9, Average = 1.84
Diaphaniety:
Transparent to translucent
Habits:
Fibrous - Crystals made up of fibers., Encrustations - Forms crust-like aggregates on matrix.,
Hardness:
1.5-2 - Talc-Gypsum
Luminescence:
None.
Luster:
Silky
Streak:
white
More details...