Variscite

Variscite PO·2H₂O, hydrated aluminium phosphate, is a relatively rare phosphate mineral. It is sometimes confused with turquoise, however, variscite is usually greener in color.Variscite is a secondary mineral formed by direct deposition from phosphate bearing water that has reacted with aluminium rich rocks in a near-surface environment. It occurs as fine-grained masses in nodules, cavity fillings, and crusts. Variscite often contains white veins of the calcium aluminium phosphate mineral crandallite.
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(n.)
An apple-green mineral occurring in reniform masses. It is a hydrous phosphate of alumina.
  

General Information:
 Chemical Formula:
AlPO4·2(H2O)
 Composition:
(Molecular Weight = 157.98 gm)
Aluminum 17.08 % Al
Phosphorus 19.61 % P 
Hydrogen 2.55 % H 
Oxygen 60.76 % O 
 Empirical Formula:
Al(PO4)·2(H2O)
 IMA Status:
Approved IMA 1963
 Name Origin:
Named after Variscia, the historical name of Vogtland, Germany.
Physical Properties:
 Cleavage:
[010] Perfect
 Color:
blue green, colorless, green, or light green.
 Density:
2.5 - 2.52, Average = 2.5
 Diaphaniety:
Transparent to Translucent
 Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Encrustations - Forms crust-like aggregates on matrix., Reniform - "Kidney like" in shape (e.g.. hematite).
 Hardness:
4-5 - Fluorite-Apatite
 Luminescence:
None.
 Luster:
Earthy (Dull)
 Streak:
white
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