Pearl Cultivation

 

Pearls is best a source of fascination since centuries past. The white iridescent gem cast an indefinable spell over mankind, so much so that all the great ancient civilizations have had an interesting association with pearls.  Pearls also warrant mention in the Holy Scriptures and legends and folklore concerning it abound.  The ancient civilizations all held pearls in great esteem; they were used as currency and were a measure of a person’s wealth and power. 

Pearls came to symbolize purity, modesty and feminine charm.  The decline of these ancient powers, resulted in the shifting of focus on Europe, whose decadent royalty submerged themselves in Pearls and the ruthless harvesting of the natural pearl oysters began.  The New World opened another door for the cannibalistic harvesting of pearls till the end of the 19th century, when the ancient pearl trade ended, simply because there was nothing left to harvest.

History of Pearl Cultivation

Pearls were probably discovered in antiquity, when man was foraging for food along the sea shore, and for innumerable years pearls were retrieved from the ocean beds by deep sea divers.  This was a risky hazardous process, as nearly three tons of oysters would yield 3 or 4 perfect pearls. 
A pearl being formed in an oyster is a miracle of nature. 

A natural pearl is formed due to the defense tactic of the oyster to an irritant which accidentally may have lodged in its mantle.  The oyster secretes Nacre a covering around the irritant which over a period of time forms a translucent pearl. 

Pearl cultivation, with human intervention, results in the formation of a cultured pearl.  Cultured pearls are identical to natural pearls and pearl cultivation is a long, patient, and surgically precise procedure.  There are two types of cultivation procedures, nucleated for sea water pearls and non-nucleated for freshwater pearls.

The odyssey for the cultivation of a pearl, which began in the year 1800, owes its beginning to the painstaking efforts of a single man, Kokichi Mikimoto.  He worked tirelessly for 12 years and in the year 1905 produced the first perfect pearl.  During the next 100 years the Japanese perfected and polished the technique to produce the matchless Akoya pearl.

The cultivation of cultured pearls begins appropriately at sea.  Since oysters cannot be artificially cultivated, they need to be dredged up from the ocean floor.  A special type of boat called the pearl boat which is fitted with two 10 metre long booms on either side and holds the towing ropes is pressed into action.  The live oysters which number to several thousands are held in the boat tanks.  Once the collection of oysters is over, the oysters are cleaned, weighed and placed in plastic nettings attached to a metal frame.  Each netting panel holds 6-9 oysters.  The oysters are transferred to a saltwater tank and taken to a holding area. 

The panels are then lowered to the sea bed to recover from the stress of capture.  After a couple of months, lying peacefully on the sea bed the panels are lifted, the oysters are opened and seeded or nucleated by expert technicians.  The procedure involves introducing into the oyster a nucleus that is an irritant and a tiny portion of another oyster’s mantle. Once the nucleation is completed the oyster in their respective panels are once again lowered to the ocean floor.  Several months pass before the panels are transported to pearl farms.

Pearl farms are situated in sheltered areas, away from pollution due to effluents, in a sparsely populated, and no cyclone area.  The pearl farms are located near high tide areas, which provide the oysters with the necessary organic food. The oysters in their panels are suspended from culture systems, tended regularly by the technicians for the next 24 months, cleaned periodically and even x-rayed to check their growth. 

In September and June months the pearls a harvested.   Once the pearls are removed from the oysters they are sorted based on shape and size.  The oysters are nucleated again and progressively produce larger pearls.

Freshwater Pearl Cultivation

Freshwater pearl cultivation is similar to saltwater pearl cultivation, the only difference being that mussels are used instead of oysters.  Freshwater pearls do not have a mother of pearl nucleus; the pearls are made up of Nacre entirely.  For seeding the mussels are gently pried open, tiny slits are cut into the mantle and living tissue from the mantle of another mussel is inserted.  As per the age and size of mussel, 20-60 pieces of mantle tissue are seeded inside.  Pearl sacs are formed around the tissue irritants and as time lapses they dissolve and pearls are formed.

After 12-18 months the pearls grow to 3mm in size.  After 3 years they grow to 7mm in size.  The mussels can provide 10 or more pearls at a time.  The mussels do not require cleaning once they are submerged in the pearl farms.  Their harvesting period is shorter and further re-seeding produces flat pearls.

Black Pearl Cultivation

Black pearl or the Tahitian pearl which is formed in the regions of the French Polynesia come in all the colors of the rainbow and hence are highly prized possessions. In the black lipped oyster, the Pinctada Margarita where mostly black pearls are formed. Pearl cultivation of the Black pearl begins by the careful farming of the young black lipped oyster known as the spat.  

Spats are collected and suspended in frames 5 meters below the surface.  Here the spats remain up to 3 years and are cleaned regularly.  As the spats mature they are further submerged up to 7 meters below surface for a period of two years. 

As they mature the oysters are ready for grafting.  The grafting of a black pearl is a delicate and long procedure.  It requires a black lipped mature spat to be pried open delicately preferably one with a brightly colored mother of pearl inside. A narrow slice of the secretory mantle of another oyster is sliced and further cut into small slices. 

A single slice is disinfected and coated over a nucleus that is a 6-9mm sphere made from the shell of a river mollusc.  The coated nucleus is then introduced into the pried open mouth of the mature spat.  Over a period of 12-18 months the pearl is formed.

Major Countries where Pearls are Cultivated

Saltwater pearls are cultivated along the Northwest Coast of Australia.  The area which produces the finest South Sea Pearls extends from Burma, the Gulf of Thailand, passing through the Sulu Sea of the Philippines, Malaysia, and the Arafura Sea of Indonesia. 

The Cook Islands, passing through Tahiti up to the Tuamoto Archipelago and the Gambier islands in the French Polynesia are credited with producing the best black pearls.  The Akoya pearls are produced in Southwest Japan.

  • China is the leading producer of freshwater pearls, followed by the Japan in the Lake Biwa.
  • India, Korea, United States, Mexico and New Zealand are recent players in the Pearl market.