| The shape of a pearl
depends very much on the shell and the whims of nature. In its efforts
to rid itself of the irritating nucleus, a shell often turns and moves
the object of its discomfort thereby creating many different shapes.
Round Pearls
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Round pearls are almost perfect spheres whose
diameter variation rate is less than 2%. The round pearl is
the most sought after and the most rare of cultured black pearls.
When a pearl is allowed two years to grow inside an oyster,
the chances of even, perfectly spherical nacre accumulation
are a long shot. Rounds rarely account for more than 10% of
a pearl farm's crop while the norm is closer to 5%. The percentage
gets even smaller, when taking into account the many round pearls
that are so heavily blemished they are unsaleable. Fine-quality
round black cultured pearls are the most rare and expensive
of the breed. However, more plentiful semi-rounds and button
shapes can give the look of round shapes for less money, especially
when these pearls are set in jewellery. In such cases, slight
deviations from round and even noticeable elongation can be
concealed or, at the very least, masked. |
Semi-round Pearls
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Semi-round pearls are slightly imperfect spheres
whose diameter variation rate is greater than 2% but less than
5%. A micrometer must be used to distinguish the difference
between a round and semi-round pearl. |
Semi-baroque Pearls
Semi-baroque pearls exhibit an axis of rotation and are subdivided
into four shapes: drop, button, pear and oval. These symmetrical
shapes are also highly prized.
Baroque pearls:
 |
Baroque pearls do not have any axis of rotation
and are asymmetrical in shape. Given the transforming impact
of design on the look of a pearl, designers that specialize
in black pearl jewelry usually admire drop and baroque shapes. |
Circle or Ringed Pearls:
Circled or ringed pearls are characterized by regular streaks,
thickened rings or furrows that are perpendicular to its axis of
rotation and cover more than a third of the pearl's surface. Sometimes
there is only one furrow or ring, but in other instances the entire
pearl is sculptured by a series of concentric furrows from one end
to the other.
Circle pearls generally account for 25-30% of a black pearl harvest.
No one knows why "circle pearls" occur so often in harvests.
Whatever the cause of ringed pearls, they often compensate for this
characteristic with pronounced color play and multiple hues.
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