Bi-colored tourmaline is an amazing
gemstone that shows two colors,
such as pink and green or pink
and blue, within a single crystal.
There is mention of bi-colored
tourmaline in books from the
early twentieth century, but
it was not until 1970s that this
gemstone became commonly used
in jewelry. It is now popular
among jewelry designers, and
one can come across adornments
that fully bring out its charm.
A bi-colored tourmaline's beauty
is judged by the balanced contrast
between its pink and light green
or light blue colors. Instead of
colors that look as through a ruby
and an emerald have been joined together,
patterns of pastel pinks and greens
(as shown to the next page) are preferred.
Tourmaline occurs in a wide range
of hues. It is mined in all colors
of the rainbow-red, orange, yellow,
green, blue, and violet- but most
of these are very dark. Bi-colored
crystals having two separate colors,
or material with three colors in
a concentric ring-shaped pattern
resembling the cross section of a
watermelon, occur in limited quantities.
Brazil, Mozambique, Nigeria, Siberia,
and California in the United States
each produce small amounts. Of these,
Brazil appears to be the largest
producer. |
Bi- or
tri- colored tourmaline occurs because
of differences in the crystal's chemical
composition, caused by changes in
the natural environment during formation.
Ai different times during the tourmaline's
formation, various color-causing
elements such as iron, manganese,
titanium, chromium, vanadium, and
copper are incorporated into the
crystal, causing layers of completely
different colors to appear.
Bi-colored tourmaline is generally
left untreated, subjected to no processing
other than polishing. Since the gem
is relatively high included, it develops
fractures and breaks when heated.
This gemstone should be treasured
for the magnificent harmony of its
two colors- a beauty that is created
by chance within the earth- as well
as for the knowledge that no two
pieces are exactly alike. |
