Pearl history...
As soon as the Spanish conquistadors arrived in the Western Hemisphere they
discovered that around the islands of Cubagua and Margarita, some 200 km north
of the Venezuelan coast, was the most exquisit bed of pearls they had seen.
One of them, the Peregrina, was offered to the Spanish queens, the same pearl,
an elongated one, that became very famous when Richard Burton purchased it
and gave it to his wife Elizabeth Taylor. Margarita pearls are extremely difficult
to find today, they have an exquisite yellowish color and are certainly unique
and far better than others. The most famous Margarita necklace that any one
can see today is the one that then Venezuelan President Romulo Betancourt gave
as a gift to Jaqueline Kennedy when she and her husband, President John F.
Kennedy paid an official visit to Venezuela.
Before the beginning of the 20th Century, pearl
hunting was the most common way of harvesting pearls. Divers manually pulled
oysters from ocean floors and river bottoms and checked them individually for
pearls. Not all natural oysters produce pearls. In a haul of three tons, only
three or four oysters will produce perfect pearls.
However, almost all pearls used for jewelry are cultured by planting a core or nucleus into pearl
oysters. The pearls are usually harvested after one year for Akoya, and 2-4
years for Tahitian and South Sea, and 2-7 years for freshwater. This mariculture process
was first developed by Tatsuhei Mise and Tokichi Nishikawa in Japan.
The nucleus is generally a polished bead made from freshwater mussel shell.
Along with a small piece of mantle tissue from another mollusk to serve as a
catalyst for the pearl sac, it is surgically implanted into the gonad (reproductive
organ) of a saltwater mollusk. In freshwater perliculture online the piece if
tissue is used in most cases, and is inserted into the fleshy mantle of the host
mussel. South Sea and Tahitian pearl oysters, also known as Pinctada margaritifera and Pinctada
maxima, which survive the subsequent surgery to remove the finished pearl
are often implanted with a new, larger nucleus as part of the same procedure
and then returned to the water for another 2-3 years of growth. Despite the common
misperception, Mikimoto did not patent the process of pearl culture. The accepted
process of pearl culture was developed by a team of scientists at Tokyo University
between 1907 and 1916. The team was headed by Tokichi Nishikawa and Tatsuhei
Mise. Nishikawa was granted the patent in 1916, and married the daughter of Mikimoto.
Mikimoto was able to use the technology after the patent expired in 1935. After
the patent was granted in 1916, the technology was immediately commercially applied
to akoya pearl oysters in Japan in 1916. Mise's brother was the first to produce
a commercial crop of pearls in the akoya oyster. Mitsubishi's Baron Iwasaki immediately
applied the technology to the south sea pearl oyster in 1917 in the Philippines,
and later in Buton, and Palau. Mitsubish was the first to produce a cultured
south sea pearl - although it was not until 1931 that the first small commercial
crop of pearls was successfully produced.
The original Japanese cultured pearls, known as akoya pearls, are produced by
a species of small oysters, Pinctada fucata martensii, no bigger than
6 to 7 cm in size, hence akoya pearls larger than 10 mm in diameter are extremely
rare and highly prized. Today a hybrid mollusk is used in both Japan and China
in the production of akoya pearls. It is a cross between the original Japanese
shell, and Pinctada chemnitzii of China.[7]
China has recently overtaken Japan in akoya pearl production. Japan has all but
ceased its production of akoya pearls smaller than 8mm. Japan maintains its status
as a pearl processing center, however, and imports the majority of Chinese akoya
pearl production. These pearls are then processed (often simply matched and sorted),
relabled as product of Japan, and exported.[8]
In the past couple of decades, cultured pearls have been produced with larger
oysters in the south Pacific and Indian
Ocean. One of the largest pearl-bearing oysters is the [[Pinctada maxima]],
which is roughly the size of a dinner plate. South Sea pearls are characterized
by their large size and silvery color. Sizes up to 14 mm in diameter are not
uncommon. Australia is
one of the most important sources of South Sea pearls. Mitsubishi commenced pearl
culture with the south sea pearl oyster in 1916 as soon as the technology patent
was commercialised. By 1931 this project was showing signs of success, but was
upset by the death of Tatsuhei. Although the project was recommenced after Tatsuhei's
death, the project was discontinued at the beginning of WWII before significant
productions of pearls were achieved. After WWII, new south sea pearl projects
were commenced in the early 1950s in Burma and Kuri Bay and Port Essington in
Australia. Japanese companies were involved in all projects using technicians
from the original Mitsubishi south sea pre-war projects. Despite often being
described as black south sea pearls, Tahitian pearls are not south sea pearls.
The correct definition of a south sea pearl is "the pearl produced by the Pinctada
maxima pearl oyster."
In 1914, pearl farmers began culturing freshwater pearls using the pearl mussels
native to Lake
Biwa. This lake, the largest and most ancient in Japan, lies near the city
of Kyoto. The
extensive and successful use of the Biwa Pearl Mussel is reflected in the name Biwa
pearls, a phrase which was at one time nearly synonymous with freshwater
pearls in general. Since the time of peak production in 1971, when Biwa pearl
farmers produced six tons of cultured pearls, pollution and overharvesting have
caused the virtual extinction of this animal. Japanese pearl farmers recently
cultured a hybrid pearl mussel — a cross between the last remaining Biwa
Pearl Mussels and a closely related species from China, the Cristaria plicata — in
lake Kasumigaura. This industry closed in 2006 due to lake pollution.
