O] typically found in the Chara River
area in Russia
. Because of its beautiful coloring, it is usually used for making jewelry.
Potassium 3.80 % K 12.88 % K2O
Calcium 17.53 % Na 24.53 % Na2O
Hydrogen 0.39 % H 3.45 % H2O
Silicon 32.78 % Si 59.14 % SiO2
Oxygen 43.75 % O
100.00 % 100.00 % = Total Oxide
Usually purple or light brown in color, Charoite is found in distinctively fibrous, fine grained forms and tiny-crystal druse on its host rock. With a density of 2.54 - 2.58 and a hardness 5.0 - 6.0, the stone is usually found in a syenite massif, in metasomatic rocks.
The stone has a Dana class of 188.8.131.52, in the Double crankshaft chain subgroup, with inosilicate column or tube structures . A very rare stone, it is highly prized for it's rich purple colors for cabs.
The highest quality pieces are opaque, and can be effectively used in jewelry. Like Sugilite, it looks beautiful set with lapis lazuli or other such blue stones as well as many others.
http://webmineral.com/data/Charoite.shtml - Contains excellent further information on optical and physical properties of the substance.