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Pearls
The pearl, symbol of purity, virtue and modesty, is also one of the most precious types
of jewellery. Technically known as "organic gems", pearls have been harvested and worn
for more than 4,000 years. Their appearance, and how they are acquired, has changed
dramatically over that time, and especially in the past hundred years. But pearl
jewellery remains a classic.
Natural Pearls
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, building the layers up for years, and creating a pearl. Natural
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, they're rare and
very costly.
Cultured Pearls
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 create 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
today's jewellery are cultured pearls.
Pearls are cultured all over the world, but Japan, China and America remain in the forefront
of production. Different types of oysters in seawater, or mollusks in freshwater, create
cultured pearls with different sizes, colours and other qualities.
Cultured pearls are rated on five different qualities:
Luster and orient
Luster is the sharpness and intensity of the reflections on the pearl's surface, and orient
is the iridescent colours one sees within the pearl. The higher the luster and orient, the
more valuable the pearl.
Colour
Colour describes both the main colour (usually white, black or yellow) and the undertone
(often pink, rose, or even green.) Pearls can also be dyed any shade according to personal
preference.
Cleanliness
This describes how many imperfections are found on the pearl’s surface. All real pearls –
natural or cultured – will have some imperfections, 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.
Teardrop-shaped pearls, for instance, 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. But you should also consider how well
matched pearls are when combined in jewellery, such as on a necklace or in earrings. Look
for pearls that are essentially the same size, colour, shape and luster. Keep in mind that
the better matched pearls there are in a piece of jewellery, the higher the cost. That's
why pearl earrings cost more than two individual pearls.
When you buy cultured pearls, remember they're fairly soft gems. They can easily be
scratched if they bump into things, or by other jewellery. Keep them separate from
harder gems in your jewellery box.
Fresh Water Pearls
Recently, techniques have been developed to culture pearls in freshwater mollusks. These are
sometimes called "Biwa pearls", after the Japanese lake where they were first developed,
but today that name should only be used for cultured pearls from Lake Biwa.
Freshwater pearls are cultivated around the world, although China is the foremost producer.
Some are spheres and used like other round pearls; some are button-shaped and used
to accent jewellery; some are blister shaped, or even Rice Crispie shaped. Large ones are
often called Mabé, which are often used in earrings and other pieces with closed backs.
Black Cultured Pearls
Black cultured pearls come from a variety of sources. The rarest are those from a
large, black-lipped oyster found in the South Seas. These oysters create large,
silver-gray to black pearls that can have other colours as overtones – the most
valuable being peacock green.
Given the rarity of South Seas black cultured pearls; enhanced black cultured pearls
can be used as an alternative. These are dyed all the way through using a process
called "French dying", which produces an even, strong colour that lasts for years.
However they're coloured, they are real cultured pearls and need to be handled with
the same care as any others.
Caring For Your Pearls
Pearls are very beautiful, but they are also delicate by jewellery standards. The
layers of nacre that make up a pearl are soft and easily damaged. Because it's
an organic compound, a pearl can easily be dulled or even eaten away by chemicals
and alcohol.
Pearls are organic and porous and can be attacked by acids such as vinegar, perfumes,
acidic body perspiration and cleaners. As a result pearls should be removed before
doing any strenuous activity such as housework and sport. Clean with a soft
cloth once removed. For necklaces the silk string will need to be replaced every
two to three years.
Pearls should also be the very last item you put on before you go out. Ensure that
makeup, perfumes and any hair products have been applied and let settle before
you loop those beautiful pearls around ones neck.
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