The pearl, symbol of purity, virtue and modesty, is also one of
the most precious types of jewelry. Technically known as
"organic gems" since they are formed by shellfish,
pearls have been harvested and worn for more than 4,000 years. The
way they are acquired - and their appearance - has changed
dramatically over time, especially in the past hundred years, but
pearl jewelry nonetheless continues to be a classic.
A pearl is formed when an irritant, such as sand or a parasite,
becomes lodged in the shell of an oyster. The oyster deposits
layers of a semi-translucent crystalline material called
"nacre" around the intruder, where it builds up in
layers like the rings of a tree. This process of building up can
continue for years, resulting in a pearl. In nature, pearls take
many years to develop and often have irregular shapes, ranging
from slightly off-spherical to twisting, bulging shapes called
"baroque." In any shape, natural pearls are rare and
very costly.
Around the beginning of the 20th century, it was learned that
if a sphere of material was placed into an oyster and the oyster
stimulated correctly, the oyster would coat the sphere with nacre,
creating an almost perfectly round pearl. The longer the pearl
remains in the oyster, the larger and more valuable the pearl
becomes. These are called "cultured" pearls. Almost all
pearls used in jewelry today, including all the pearls sold by UsedJewelry.Net Jewelers,
are cultured pearls. Pearls are cultured around the world today,
and different types of oysters - or mollusks in freshwater -
raised in different environments create cultured pearls with
different sizes, colors and other qualities.
Cultured pearls are rated on five different qualities:
Luster and orient: Luster is the sharpness and intensity
of reflections on the pearl's surface, and orient is the
iridescent colors one sees within the pearl. The higher the luster
and orient, the more valuable the pearl.
Color: Color describes both the main color (usually
white, black or yellow) and the undertone (often pink, rose, or
even green.) In addition, pearls can be dyed any shade to meet
personal preference.
Cleanliness: Describes how many imperfections are found
on the surface of the pearl. Some imperfections are expected on
all real pearls, natural or cultured, but the fewer and less
noticeable they are, the better.
Shape: In general, spherical pearls are the most prized.
However, it is common to find small imperfections of shape, which
can sometimes be desirable as long as they are symmetrical. For
example, teardrop shaped pearls are often used in earrings and
pendants.
Size: Cultured pearls are sold by diameter, measured in
millimeters. In general, larger cultured pearls are rarer and more
costly. Price rises significantly with the size of a pearl.
In addition, one should look at how well matched pearls are
when combined in jewelry, such as on a necklace or in earrings.
You should look for pearls that are essentially the same size,
color, shape and luster. Keep in mind that the more well-matched
pearls there are in a piece of jewelry, the higher the cost.
That's why pearl earrings cost more than two individual pearls.
When you buy cultured pearls, keep in mind that they are fairly
soft as gems go. They can be scratched easily if they are bumped
into things, and can also be scratched by other jewelry they might
come into contact with. Keep them separate from harder gems in
your jewelry box.
Cultured pearls are commonly divided into three broad
categories:
