The History of Black Pearls
These black pearls are produced by the Pinctada Margaritifera pearl oyster, which is found in the French Polynesian Islands and Tahiti in the South Pacific Ocean. The Pinctada Margaritifera is a saltwater oyster that can grow to the size of a dinner plate. It secretes a black pigment that causes black pearls to form.
The Pinctada Margaritifera pearl oyster is a mollusk that feeds on plankton. It is cultivated in the lagoons of French Polynesia. Tahiti cultured black pearls are formed inside the pearl oyster. They consist of organic substances and calcium carbonate in the form of aragonite.
How black pearls are formed?
The seeding of pearls is done by highly skilled technicians, most of whom are Japanese. They are among the highest paid workers in the world and are booked for years in advance. The pearl oyster is collected and a technician implants a nucleus and mantle in it.
The nucleus is a small sphere of crushed Mississippi river mussel from Tennessee, which is specially bred for this purpose. The mantle is the part of the oyster tissue that forms the mother of pearl coating, which is called the nacre. The mantle creates a pouch around the nucleus.
Over a period of about two years, it lays thousands of layers of nacre over it, forming a black pearl.
The oyster shells have to be kept in a good condition so that they can withstand the trauma of the implant. This involves cleaning them regularly, to prevent barnacles and algae from building up. A lot of time and effort is required for maintaining the oyster shells in a good condition.
Tahiti cultured pearls are produced from a grafting of the Pinctada Margaritifera pearl oyster. The nucleus or the seed can not be seen in these pearls and there is a continuous pearly layer over al least 80 % of the pearl's surface. A pearl that does not meet these standards, is declared to be a rejected pearl.
Tahiti black pearls are formed by human intervention. Natural pearls are still found but they are very rare. Out of 15000 pearl oysters, only one may produce a natural pearl.
Types of black pearls
The pearls can be from 8 to 18 millimeters in size. Pearls from Tahiti come in a wide range shapes, sizes and colors. The colors range from black to silver. They are also found in shades of blue, pink and green. The cost of a Tahitian pearl may range from $ 10 to $ 10000, depending on the size and the quality.
Pearls are graded according to their size, shape, color, surface characteristics and luster. Cracks, spots, bumps, ridges and pits on the surface can affect the price of the pearl.
Pearls are found in several shapes, which include round and pear shaped pearls. Button pearls are flat on one side and round on the other and circled pearls have a ring. Baroque pearls are irregular in shape. The luster depends upon the reflection of light from the surface of the pearl. The color of the pearls can range from white to silver to black.
Sometimes the pearl oyster rejects the nucleus but the donor mantle remains. This leads to the formation of a small irregular seedless pearl, which is called a Keshi pearl.
Mabe (mar-bay) pearls are heart shaped, oval or tear-drop shaped pearls, which often display all the colors of the spectrum. They are formed by cutting the nucleus in half and attaching it inside the lip of the pearl oyster. They are also known as blister pearls and are ideal for making rings or pendants.
The golden pearl (poe pipi) is very rare and is found in the Cook Islands. It is found in the shell of the Pinctada Maculata pearl oyster, in the lagoon of Penrhyn and is seldom more than 8 millimeters in diameter.
History of the Tahiti black pearls
Jean-Marie Dormand, a Frenchman is known as the father of cultured black pearl cultivation. In 1961, he arranged to bring a Japanese pearl oyster technician to Tahiti, through the French Polynesian government. Black pearls were first cultured on an experimental basis, in the lagoons of the French Polynesian islands of Bora Bora and Hikueru.
About 1000 pearls were harvested in 1965. The first privately owned pearl farm was started in 1966 by Jacques and Hubert Rosenthal, on the atoll of Manihi. Tahitian black pearls were first exported in 1972. By the mid-1970s there was a rapid growth in awareness and demand for Tahitian back pearls.
Large scale farms were established on the islands of Mangareva, Marutea and Sud. By 1996, black pearl farms were exporting $ 152 million worth of black pearls. Robert Wan set up the farm on Mangareva and it now produces 60% of the output of black pearls.