Valencianite is a unique
variety of Adularia, which is a
variety of Orthoclase
which belongs to the large group
of minerals known as the Feldspar Group. Valencianite
was named in 1830 by Johann Friedrich August Breithaupt (1791-1873), a
German mineralogist, for the first occurance at the
Valenciana Mine, Guanajuato, Mun. de Guanajuato, Guanajuato, Mexico. The
Valenciana Mine is a silver and gold mine reaching a depth of about 1,800 feet.
The mine began operation in 1774 and has accounted for two-thirds of the world’s silver production.
Waldemar Lindgren was the first writer
to emphasize the occurance of Orthoclase as a vein mineral
in 1898. The name
revived by Lindgren, who suggested
Valencianite is a better name to use for vein
Orthoclase than Adularia because vein Orthoclase is not usually
clear and glassy like typical Adularia. Valencianite
specimens consist of sharp, pearlescent, snow-white Valencianite blades accented with small Quartz and Calcite
crystals are subtransparent and up to 2 cm in length,
showing stout prismatic habit.
distribution: at the type locality at Valenciana Mine, Guanajuato, Mun. de Guanajuato, Guanajuato, Mexico.
At the Seikoshi mine, Shizuoka Prefecture, Japan. At
at Rhonegletscher, Switzerland. In the US at Silver City,
Idaho and Cripple Creek, Colorado. Vein Orthoclase
has also been recorded from several localities in Germany,
Austria, Norway, New Zealand and Mexico.