Black
pearls come from the Pinctada Margaritafera species of
oysters, also popularly known as the giant black-lipped
oyster. These oysters grow and cherish in the warm lagoons
of Northern Cook islands of Manihiki and Penrhyn. A new
industry of pearl cultivation developed in the Northern
Cook islands. In November 1997 the great cyclone in
Manihiki gave a great shook to this industry. However
companies have started to reestablish the farms and start
the cultivation. The shell of the Pinctada Margaritafera
is exceptionally beautiful, and the oyster was heavily
fished for the shell, a source of mother of pearl for
buttons and decorative inlay. Growing the black-lipped
oysters is a highly skilled process. The grayish-black
nacre of the oyster provides the black pearls their
lustrous color. However price determination of these
pearls is not just governed by the color alone.
Pearl development is a hectic and very tedious process. At
certain times of the year, the oysters release sexual
substances that are fertilized in the water. These young
oysters, known as seed oysters, swim around for a few
weeks before attaching themselves to coral. The pearl
farmer catches these seed oysters and attaches them to
underwater rearing lines like those at the right.
Unfortunately, like most farm crops, you can't then just
sit back and watch the oysters grow. The farm family must
remove the oysters from the water about every three months
and wash them with a spray hose to remove any algae that
have grown on the shells and prevent the algae from
killing the oysters. The pearl farmers either raise pearl
oysters or divers collect three to five year old oysters
to be implanted with the nucleus. The oyster is collected
and a trained professional inserts a nucleus into the
shell and a piece of mantle from a donor shell.
Technicians, majority of them being Japanese, that seed
the pearls are highly skilled and most handsomely paid
professionals. Mantle is a small part of an oyster flesh
that lays down the mother-o-pearl coating called the
nacre. This mantle creates a pouch around the nucleus and
within two years or more thousands of very thin layers of
nacre over it. Hence a pearl is created.
Grading of pearls is done according to the color, size,
shape, luster and surface characteristics. Generally the
size of these pearls lies between 8 to 12 millimeters,
rare ones reaching a size of 13 to 15 millimeters. Pricing
of the pearls depends on the size and their quality.
Luster is the primary factor determining the quality of
the pearl, it is caused by the reflection of light from
the pearl surface. Surface of pearls can have pits, bumps,
cracks, ridges or spots, which determine the quality.
Black-lipped oysters are extremely fragile and require
lavish care and attention from their farmers. The first
successful harvest of cultured black pearls was in 1963 in
the lagoon of Bora Bora. Government, industry groups, and
associated non-profit organizations have worked hard both
to protect the native oyster populations and to assure the
superior quality of black pearls.
