Ammonioalunite

General Information:
 Chemical Formula:
(NH4)Al3(SO4)2(OH)6
 Composition:
(Molecular Weight = 393.15 gm)
Aluminum 20.59 % Al
Hydrogen 2.56 % H 
Sulfur 16.31 % S 
Nitrogen 3.56 % N 
Oxygen 56.97 % O 
 Empirical Formula:
(NH4)Al3(SO4)2(OH)6
 Environment:
Acidic hot springs with temperatures below 100 deg C and low potassium content of the waters.
 IMA Status:
Approved IMA 1987
 Locality:
The Geysers, Sonoma County, California, USA.
 Name Origin:
Named for its composition (Ammonia, Al,).
Physical Properties:
 Cleavage:
[???] Good
 Color:
gray white or white.
 Density:
2.4
 Diaphaniety:
Transparent to Translucent
 Habits:
Efflorescences - Crystals covering matrix, generally produced from transpiro-evaporation., Massive - Granular - Common texture observed in granite and other igneous rock., Rhombohedra l Crystals - Occurs as well-formed cryst
 Hardness:
2-3 - Gypsum-Calcite
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
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