Pearls - a treasure from the ocean

Pearls don’t need polishing or faceting to reveal their natural
beauty. That’s why pearls were among the first gems worn by humans.
The oldest known pearl necklaces graced the necks of women more than
4,000 years ago.

Some early stories say pearls grew from the tears of a goddess.
Others tell of oysters swallowing raindrops or dewdrops that fell
into the ocean. Round and lustrous, pearls symbolize the moon, and
mortals have universally assigned feminine characteristics to them.
Those who value gems for their powers wear pearls to attract love
and good health.

Pearls are classified as organic gems because they are made by
animals called mollusks. Mollusks have shells and most of them live
underwater. They secrete a natural substance called nacre (rhymes
with “acre”).

Nacre consistes mainly of aragonite, a mineral crystal from the
calcium carbonate family. The aragonite is combined with a natural
"glue" called conchiolin and small amounts of water to form nacre.
Nacre is also known as mother-of-pearl. The purpose of nacre is to
make the inside of the shell smooth so that it doesn’t irritate the
soft body of the mollusk. A pearl is simply an abnormal growth of

Natural pearls are formed when something such as a grain of sand
gets inside the shell and irritates the mollusk. To reduce the
irritation, the animal covers it with thousands of smooth layers of
nacre. The process is similar to what your body does when it forms a
callus to protect irritated skin. It takes about three years to grow
a small pearl.

Cultured pearls differ from natural pearls in that the irritant,
usually a bead, is placed in the oyster by man. As cultured and
natural pearls look alike, only an expert with special X-ray
equipment can distinguish between them. Cultured pearls may not be
sold as natural; however, they are regarded as “real” pearls and not
fakes. Nearly all pearls on the market today are cultured, with most
of them coming from Japan.

Pearls grow in many shapes, with round being the most highly prized.
Some other symmetrical (even) shapes are pear, bell, and drop. A
baroque pearl is one that is irregular in shape. Skilled jewelers
often take advantage of the odd shapes of baroque pearls to make
unique jewelry. Most popular are those shaped like animals or
humans. If a pearl is rounded on one side, but flat on the other, it
is known as a bouton. Blister or button pearls are other names for

Because the nacre is deposited in overlapping layers, it doesn’t
reflect light evenly. This creates iridescence and the lustrous
inner glow of pearls. The quality of the luster depends on how many
layers of nacre have been deposited, which depends on how long the
pearl has been in the mollusk. The more layers of nacre, the greater
the luster of the pearl. The water trapped between the layers also
adds to the luster.

Iridescence is also known as orient. The most beautiful pearls are
prized because of their high orient. Saltwater pearls, which are
grown in pearl oysters, usually have more orient than those from
freshwater mollusks. Because of this, saltwater pearls have become
generally known as orientals, regardless of where they are

The pearl oyster is found in several seas. The oldest fisheries are
in Sri Lanka, but pearls from the Persian Gulf are often regarded as
the highest quality. Each pearl oyster, which is not edible,
normally produces only one pearl and dies when the pearl is removed.

The mussels that produce freshwater pearls are found in lakes and
rivers throughout the world.

Both cultured and natural pearls range in color from white through
rose, yellow, and blue to dark gray. Black pearls are rarely a true
black. They are usually dark gray, but may also be bronze or
gun-metal colored. An even or deep black pearl is often the result
of “treating” the pearl with silver nitrate. Some “black pearls” are
really polished hematite. While shiny, hematite lacks the glow of a
true pearl.

All pearls may be dyed or stained, although coloring is more common
with freshwater than saltwater pearls. Dying is usually undectable,
except under strong magnification. Peroxide is sometimes used to
bleach out surface discoloration on cultured pearls. Bleaching
cannot be detected.

Fake pearls have been made for more than 400 years. Fish scales are
used to prepare pearl essence. The essence is used to coat glass or
plastic beads to manufacture simulated, imitation, or artificial
pearls. Fakes are easy to detect. They feel smooth if gently drawn
across the edge of your teeth. Natural and cultured pearls will
always feel gritty or rough.

Pearls are soft and easily scratched. Wipe them with a soft cloth
after wearing, then store them in a soft leather or cloth bag where
they can “breathe.” Pearls stored in plastic or in dry and airless
places like safe deposit boxes will soon lose their special glow.
Body oils, perfumes, hair spray, and make-up will stain pearls.
Never put pearls in an ultrasonic cleaner or expose them to strong
chemicals. Even mild acids will dissolve them. Because natural and
cultured pearls are so soft, the drill holes will become enlarged if
they are loosely strung and allowed to slide on the thread.
Necklaces should have a knot between each pearl, and should be
restrung professionally every year or so to prevent excessive wear
on your treasures from the ocean.

****Sandra I. Smith, Writer ****