Most yellow and brown Topaz,
and the popular blue varieties that are derived from
them, gain their coloration from natural atomic phenomenon
present within the gems
Mention the word irradiation and
most people will run a mile. Ironically, these same
people will think nothing of heating up their lunch
in a microwave, soak in the Suns' ultra-violet rays,
bug out in front of their TV's gamma rays and chat
away via radio waves on their cell-phones. In truth,
radiation is all around us, part of our everyday existence
and an integral ingredient of our genetic make-up.
A linear accelerator bombards these
with high-speed electrons: subatomic negative charges.
These electrons pierce the crystal structure, hit
molecules and displace atoms. When part of an atom
is displaced from its regular site, its place is taken
by one of the electrons, which becomes trapped in
the vacant space. This trapped electron absorbs light
energy, which causes it to get excited and jiggle.
This light energy is dissipated through the motion
of the excited electron, and with it a subset of color
wavelengths from the light energy is used up. What
we see as the colors of a Topaz
are the remaining light energy wavelengths, which have
not been used up by the excited electron. This is
the creation of a'Color Center,' the phenomenon that
amethyst and some colored diamonds their color.