Natural pearls are formed when an irritant becomes lodged
in a pearl oyster, and gets coated with a natural secretion
of calcium carbonate called nacre. In the beginning of the
1900's, it was discovered that a spherical bead could be
placed in an oyster, and pearls could be "cultured". There
are varieties of fresh water mollusks that also produce
pearls. These pearls can be cultured by artificially embedding
bits of muscle tissue into the bivalves. Over ninety per
cent of the pearls sold today are cultured, not natural.
The great majority are also treated in some way to improve
their appearance and color. The most enduring legend concerning
pearls, is the story of Cleopatra dissolving pearls in the
wine she drank in Mark Antony's presence. Truth be told,
wine, nor anything else safely drinkable by humans, would
be able to dissolve a pearl!
Oyster
Varieties:
Black-Lip
Oyster: An
oyster of unusual size and diameter found in the South Pacific,
from which is derived the famous black pearls known in the
industry as Tahitian Pearls. Other colors produced by this
mollusk, besides black, are silver to light gray, dark gray,
orange, gold, green, blue, and purple.
Gold-Lip
Oyster: The
large oyster, found in the waters off Australia, Indonesia,
Philippines and Japan, which produces gold-colored South
Sea Pearls.
Pinctada
Fucata: The industry term for the saltwater mollusk that produces
Akoya cultured pearls.
Pinctada
Maxima: The industry term for the White-lip oyster that produces
South Sea Pearls.
Pinctada
Margaritifera: The industry term for the saltwater mollusks that
produces Tahitian cultured pearls.
Uniondae
Hyriopsis Schlegeli: The freshwater mussel, prevalent in China,
which produces a strong pearl with thick nacre and a bright luster. Its
pearls come in a palette of colors ranging through plum, lavender, peach,
apricot, curry, red pepper, cinnamon, celery and sage.
White-Lip
Oyster: Large oysters found in the waters around Australia, Indonesia,
the Philippines and Japan, and producing good-sized South Sea cultured
pearls whose tints include silver-white, pink and cream.