They have been irradiating pearls for quite awhile. Usually
they turn the pearls black with the process. For awhile there
were quite a few black rice krispie freshwater pearls on the
market. You still can see them around.
Irradiated is a new treatment that came out a few years ago. It
is more stable than dyed pearls, they have a tendancy to
dissapate. You can always tell the dyed pearls they have a
spongy look to them.
Dwyn: Aside from the horrably expensive natural black pearl,
there are two imitations, the irrariated and dyed. Seems they’re
origionaly shades of brown or other undesireable colors and
treated to become black. The dyed are slightly cheaper but
neather is expensive. I have been told that eather type is
stable however, I have noticed the dyed often vary in color. I
suspect your friend was showing you a pearl treated with
titanium salts to make it mult-colored. Perhaps this one just
did’nt take well to the treatment.
Actually, the dyed ones do decompose in time. The irradiation
techniques were first introduced on very low end Thaitians! You
can tell the difference between dyed and irradiated. Irradiated
looks more natural and not so inky!
Hi everybody: I had a strand of pearls come in for an appraisal
a couple of months ago, they were black with golden highlights
and the sheen looked almost like the golden obsidian beads. The
treatment was so bad, or old that the nacre was brittle and
coming off on some of the pearls really strange lookin stuff.