The mollusk used to produce
saltwater cultured pearls. It is found in Japan, China, throughout
East Asia, the Indo-Pacific area, the Red Sea, Persian Gulf, Mediterranean
Sea, South Africa and in the Caribbean
Biwa Pearls
Cultivated with Hyriopsis schlegeli in Lake Biwa, Japan, the country's largest freshwater lake.
Environmental conditions have contributed to the demise of pearl production.
Chinese "Biwa" have the characteristic softly rounded rectangular
shape and are usually called "Biwa" even though they are
not from Japan
FWCP
Commonly used abbreviation
for freshwater pearls. FWCP is technically the correct form indicating
that the pearls are freshwater cultured pearls.
Grafters
Technicians who cut strips
of mantle tissue and insert it into the mussel or mollusk
Hyriopsis cumingii
The Chinese "triangle
mussel" used as both donor of the mantle tissue and for culturing
freshwater pearls
Iridescence
The interplay of light
and color on the surface of the pearls in which the reflection and
interference of light waves produce a rainbow of changing color. This
is a component of orient
Luster
The most important quality
in evaluating the beauty of a pearl. It is the reflection of light
on the surface layers of nacre. The brightest reflections are the most
desirable
Mollusk
Chiefly salt water invertebrates
with a mantle, a soft body, and a protective calcareous shell pearls
are grown in oysters, clams and abalone, all mollusks
Mantle
The tissue surrounding
the soft body of a mollusk is also known as the epithelium. It is made
of epithelial cells that secrete the nacre that forms the shell and
forms the pearl sacs. In this way, the mollusk protects its delicate
soft tissues from irritation or infection
Mussel
A generic name for certain
types of freshwater bivalve mollusks with a dark, elongated shell.
Most freshwater pearls are cultivated from the freshwater mussel family,
Unionide. Today, the species most widely used is Hyriopsis cumingi
Nacre
The combination of microscopically
think platelets of calcium carbonate crystals that are cemented together
by conchiolin, an organic protein glue that creates nacre. This is
the substance of which pearls are composed
Nucleus
Most freshwater pearls
are tissue-nucleated using the mantle tissue of the mollusk. Some are
shell-nucleated using a piece of preformed shell and a piece of mantle
tissue. These are typically pearls in specific shapes of coins, squares,
hearts, etc. Most saltwater pearls are implanted with a preformed sphere
of shell and a piece of mantle tissue as well
Orient
As light rays strike the
surface of a pearl, it interacts with each microscopic layer in a slightly
different way. This interference causes light to break up into its
component colors, much like a prism. This creates this rainbow effect
or orient
Oyster
A bivalve, saltwater mollusk used for cultivating South Sea, Tahitian, Philippine, Australian and Akoya pearls
Pearl
A nacreous growth that
forms around an irritant such as a piece of tissue and/or bead in order
to protect the mollusk, and produces a pearl. If the irritant occurs
naturally, the pearl is a natural/genuine pearl. Most pearls in the
marketplace are grown by man and are cultured pearls
Pearl Farm
These are sites dedicated to cultivating pearls. Freshwater pearl farms nucleate mantle tissue and/or shell pre-forms in mussels and grow them to maturity in lakes. South Sea producers breed oysters in controlled conditions and nucleate them with a shell bead and mantle tissue. They are grown out in bays and oceans cared for to full maturity. In Tahiti, young oysters called spats are collected in lagoons for production. In some cases, one farm breeds the young oysters (spats), others perform the nucleation then other farms may tend to them until they are ready for harvest.
Periculture Pearl
Cultivation or pearl farming:
the practice of inducing pearl formation in mussels/oysters by implanting
with tissue and/or shell
Pinctada margaritafera
Mollusk that cultivates hues of black pearls from Tahiti, the Cook Islands
and other parts of the South Seas
Pinctada maxima
Mollusk that cultivates white, golden and silver pearls from Australia, the Philippines, Indonesia and other parts of the South Seas
Bibliography
Akamatsu, Shigeru, Zansheng,
Li Tajima, Moses, Thomas M., & Scarratt, Kenneth, "The Current
Status of Chinese Freshwater Cultured Pearls," pp.96-113, Gems & Gemology,
Summer 2001, Volume XXXVII. GIA, Carlsbad, CA 92008
GIA Course on Pearls,
Carlsbad, CA 92008, 1999
Joyce, Kristin & Addison,
Shellei, Pearls, Ornament & Obsession, Simon & Schuster, New
York, NY 10020, 1999
Landman, Neil H., Mikkelsen,
Paula M., Bieler, Rudiger & Bronson, Bennet, Pearls: A Natural
History, Harry N Abrams, Inc. in association with The American Museum
of Natural History & The Field Museum, New York, NY, 2001
Muller, Andy, for the
Golay Buchel Group, Cultured Pearls, the First Hundred Years, International
Ad Co., Osaka, Japan, 1997
Gail Brett Levine, GG
Publisher, Auction Market Resource - the book. Your prime sources
for prices of gems and jewelry sold at auction.