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The
red tourmaline (rubellite) from California, illustrated in the
accompanying colored plate, is found in San Diego County of that State.
The matrix in which it occurs is a lithia-bearing mica (lepidolite ) of
a delicate violet color. In this matrix the tourmaline usually occurs
in radiating masses. The rose color of the tourmaline contrasting with
the violet of the lepidolite makes an object which is quite a favorite
with mineral fanciers, although the former is not sufficiently
transparent to be used as a gem. At two other localities in the same
State large transparent tourmalines of varying colors have been found.
Tourmaline
is found frequently in Brazil in the gem gravels, accompanying topaz,
amethyst, diamond, etc. It is mostly green in color, and is known as
Brazilian emerald, it having been for a time mistaken for emerald.
In
the Ural Mountains, near Ekaterinburg, crystallized tourmaline occurs
in cavities in granite, accompanying amethyst, beryl, topaz, etc. These
crystals often have a fine dark red color, and produce the gems known
as Siberian rubies. They are especially prized in Russia.
Although
the name tourmaline came from Ceylon, the gem there known by that name
is hyacinth. True tourmaline occurs, however, on the island in the gem
gravels. This is usually of a yellowish-green color, and is often known
as Ceylonese chrysolite. '
On
the Island of Elba are also obtained tourmalines, generally red in
color, transparent, and well crystallized. They are, however, not
extensively used as gems, on account of their small size.
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