| April 1998
For Your Staff:Selling Pearls
On the Surface
When the oyster yields a smooth, blemish-free pearl, it's a triumph
of nature and one mark of high quality
by Devin Macnow Executive Director Cultured Pearl Information Center
Think of good-quality pearls and you'll likely think of smooth surfaces.
In fact, surface is the second most important aspect in evaluating a cultured
pearl after luster.
Surface quality refers specifically to the abundance or absence of physical
blemishes or flaws. When evaluating surface (the trade uses such terms
as blemish, spotting and cleanliness), remember that cultured pearls are
grown by live oysters in nature. As such, there are many uncontrollable
forces that affect the surface.
Environmental conditions combined with the relative health and genetic
perfection of the host oyster, for example, play key roles in determining
the perfection of a pearl's surface. In fact, fewer than 1% of all cultured
pearls have surfaces that are perfectly smooth or completely free of surface
flaws. Even the highest-quality cultured pearls may have a little spotting
or blemishing. Naturally, the fewer the blemishes, the more valuable the
pearl.
Two Types of Flaws
The most common flaws or blemishes are divided into two categories: damaging
and non-damaging.
Non-damaging flaws don't affect lifespan or durability. They do affect
aesthetic beauty, appearing as bumps, pits, welts or wrinkles. They're caused
by excess or irregular nacre buildup on the core nuclei of a cultured pearl
during the long growing process.
In the case of non-damaging blemishes, it's their relative abundance
or absence that determines the pearl's quality and price. In some instances
where blemishes occupy over 25% of the surface, the value can drop by half.
And just because a pearl may seem to be blemish-free now doesn't guarantee
it was never flawed. Quite often jewelry manufacturers select a blemished
area to drill the hole necessary for future stringing and setting. This
isn't a deceptive procedure; it's merely a practical way to eliminate a
blemish while making the pearl ready for jewelry finishing.
The Question of Durability
Damaging flaws such as chips, cracks and pinholes not only detract from
the overall beauty of a pearl, but also may influence durability. They also
tend to become larger over time and cause the nacre to peel or chip, damaging
the pearl and lowering its value.
Drilling can create cracks and chips near the drill hole if the technician
makes an error in his calculation. Or perhaps the nacre was brittle and
cracked under the severe heat and pressure of drilling.
Other damaging flaws may be caused by irregular nacre formation. These
include pinholes, which penetrate deep into the layers of nacre and may
expose the core nuclei. These also tend to enlarge through regular wear
and can become clogged with dirt.
It's important to note that virtually all pearls have some spots or blemishes,
so examine them carefully to determine their severity and their capacity
to affect the pearl's lifespan. If non-damaging flaws can't be seen by the
naked eye from a distance of two feet, for example, they're likely not serious
and won't detract from the pearl's overall beauty. In fact, pearls with
high luster often can mask small surface flaws.
Though the surface is an important basis to evaluate quality, there is
one exception: low-quality pearls are often smooth and free of visible surface
imperfections simply because there's not enough nacre to create a blemish.

Here are examples of a range of cultured pearl surface quality. The pearl
at left has a damaging pinhole. Beside it is a pearl with a damaging chip
and crack. Next are non-damaging bumps and pits, then non-damaging wrinkles
and finally a blemish-free pearl.
Copyright © 1998 by Bond Communications.
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