For Seller

By: Kathy Abdelhak

All pearls are processed in some way. Akoya and
Freshwater pearls are bleached, and all pearls are
cleaned and polished before they are sold. There
are some treatments to take note of on cultured
pearls that will change the aesthetic qualities of
the pearl.

After harvesting cleaning and polishing a
low-quality cultured pearl if the pearl still does
not have a good luster or color, the farmer has
very few options. If the pearls is a good
candidate for treatment, this is the most common
and economically sensible thing for the farmer to
do. There are three main treatments are used on
low-quality pearls.

Dyeing- The use of silver nitrate to darken the
nacre of the pearl. Irradiation- The use of gamma
rays to darken the nucleus of the pearl in akoya
pearls and the nacre layers in freshwater pearls.
Luster treatments- A coating is placed on the
surface of the pearl to enhance the luster.

Silver nitrate has been used for decades to darken
the appearance of the peal. The chemical
penetrates the layer of nacre and has a chemical
reaction with light or hydrogen sulfides gas to
organic or inorganic dyes to produce another color
variation. This treatment is very popular in
treating fresh water pearls. Sometimes the farmer
will want to create other colors then black the
farmer in this case can use organic or inorganic
dyes to make the color variations. Akoya pearls
are also routinely "pinked" this is done when they
would like to make a more rose overtone.

Irradiation has a different effect on freshwater
to saltwater and cultured pearls. Gamma rays do
not affect the nacre layers of a saltwater
cultured pearl, but will darken the nucleus of the
pearl. Saltwater pearls that are irradiated will
be gray to blue. Freshwater irradiated pearls can
become very dark, some of these freshwater treated
pearls may also have an intense metallic sheen
over their surface.

Coating a pearls to enhance its luster is not
widely practiced and is frowned upon. The coating
is like putting clear nail polish. The coating may
eventually chip or peel, leaving a low-luster
pearl this is a treatment to watch for.

Luster treatments are very hard to find. The most
basic way to find the luster treatment is to
compare an untreated strand with the strand that
you think has been treated. You can put the strand
under 50x magnification. The untreated pearl will
have a scaly nacre surface and the coated pearl
will have a smooth, glass like surface.

All pearls are processed in some way. You as the
pearl consumers should be aware of all the
treatments before you are going to buy these
classic beauties to add to your jewelry
collection.

Kathy Abdel-Hak is Co-Owner of N.J.Diamonds located in dearborn, MI. You can find more information on diamonds,diamond jewelry, diamond engagement rings and gem stone jewelry at http://www.njdiamondsonline.com or njdiamonds.typepad.com