Adelite

The rare mineral adelite, is a calcium, magnesium, arsenate with chemical formula CaMgAsO4OH. It forms a solid solution series with the vanadium bearing mineral gottlobite. Various transition metals substitute for magnesium and lead replaces calcium leading to a variety of similar minerals in the adelite - duftite group.
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General Information:
 Chemical Formula:
CaMg(AsO4)(OH)
 Composition:
(Molecular Weight = 220.31 gm)
Calcium 18.19 % Ca
Magnesium 11.03 % Mg
Arsenic 34.01 % As
Hydrogen 0.46 % H 
Oxygen 36.31 % O 
 Empirical Formula:
CaMg(AsO4)(OH)
 Environment:
In manganese deposits ar Langban.
 Locality:
TL: Sweden, V„rmland, Filipstad, L†ngban mn
 Name Origin:
From the Greek for indistinct, for its occurrence as massive.
Physical Properties:
 Cleavage:
[???] Indistinct
 Color:
blue gray, green, gray, yellow, or light green.
 Density:
3.73 - 3.79, Average = 3.76
 Diaphaniety:
Transparent
 Habits:
Massive - Uniformly indistinguishable crystals forming large masses., ,
 Hardness:
5 - Apatite
 Luminescence:
Non-fluorescent.
 Luster:
Resinous
 Streak:
white
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