General Information:
Chemical Formula:
MgAl2(SO4)4·22(H2O)
Composition:
(Molecular Weight = 858.86 gm)
Magnesium 2.83 % Mg
Aluminum 6.28 % Al
Hydrogen 5.16 % H
Sulfur 14.93 % S
Oxygen 70.79 % O
Empirical Formula:
MgAl2(SO4)4·22(H2O)
Name Origin:
Named after J. Pickering (1777-1846).
Physical Properties:
Cleavage:
[010] Indistinct
Color:
colorless, yellowish white, reddish white, or greenish white.
Density:
1.8 - 1.85, Average = 1.82
Diaphaniety:
Transparent to translucent
Habits:
Fibrous - Crystals made up of fibers., Reniform - "Kidney like" in shape (e.g.. hematite)., Encrustations - Forms crust-like aggregates on matrix.
Hardness:
1.5-2 - Talc-Gypsum
Luminescence:
None.
Luster:
Silky
Streak:
white
More details...