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How pearls are formed and their various types
There
are essentially three types of pearls: natural, cultured and imitation.
A natural pearl (often called an Oriental pearl) forms when an
irritant, such as a piece of sand, works its way into a particular
species of oyster, mussel, or clam. As a defense mechanism, the mollusk
secretes a fluid to coat the irritant. Layer upon layer of this coating
is deposited on the irritant until a lustrous pearl is formed.
A
cultured pearl undergoes the same process. The only difference is that
the irritant is a surgically implanted bead or piece of shell called
Mother of Pearl. Often, these shells are ground oyster shells that are
worth significant amounts of money in their own right as
irritant-catalysts for quality pearls. The resulting core is,
therefore, much larger than in a natural pearl. Yet, as long as there
are enough layers of nacre (the secreted fluid covering the irritant)
to result in a beautiful, gem-quality pearl, the size of the nucleus is
of no consequence to beauty or durability.
Pearls
can come from either salt or freshwater sources. Typically, saltwater
pearls tend to be higher quality, although there are several types of
freshwater pearls that are considered high in quality as well.
Freshwater pearls tend to be very irregular in shape, with a puffed
rice appearance the most prevalent. Nevertheless, it is each individual
pearls merits that determines value more than the source of the pearl.
Regardless
of the method used to acquire a pearl, the process usually takes
several years. Mussels must reach a mature age, which can take up to 3
years, and then be implanted or naturally receive an irritant. Once the
irritant is in place, it can take up to another 3 years for the pearl
to reach its full size. Often, the irritant may be rejected, the pearl
will be terrifically misshapen, or the oyster may simply die from
disease or countless other complications. By the end of a 5 to 10 year
cycle, only 50% of the oysters will have survived. And of the pearls
produced, only approximately 5% are of substantial quality for top
jewelry makers. From the outset, a pearl farmer can figure on spending
over $100 for every oyster that is farmed, of which many will produce
nothing or die.
Imitation
pearls are a different story altogether. In most cases, a glass bead is
dipped into a solution made from fish scales. This coating is thin and
may eventually wear off. One can usually tell an imitation by biting on
it. Fake pearls glide across your teeth, while the layers of nacre on
real pearls feel gritty. The Island of Mallorca is known for its
imitation pearl industry.
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