How cultivated pearls are grown and harvested

Thuan San
By Thuan San
February 23, 2017Entertainmentshare
How cultivated pearls are grown and harvested


Technicians open the live pearl oysters then gently to implant a small shell bead along with a tiny piece of mantle tissue. This bead is the nucleus around which the oyster secretes layer after layer of nacre, the substance that forms the pearl. This step of the culturing process requires tremendous skill and precision, and the oysters will only allow their shells to be pried open 2 to 3 centimetres or they will reject the nucleus. Experienced technicians use exacting tools to make the tiny incisions.


The nucleated oysters are quickly returned to the sea, housed in individual mesh pockets suspended from floating rafts. The oysters feed and grow in sheltered bays rich with natural nutrients. As time passes the oysters secrete lustrous layers of nacre around the implanted bead. In winter, the oysters are moved to warmer waters. Pearl technicians monitor water temperatures and feeding conditions daily at various water depths, and move the oysters to take advantage of ideal growing conditions.

Pearl diving

Periodically, the pearl-bearing oysters are lifted from the sea for cleaning and health care. Seaweed, barnacles and other growths are removed from the shells, and they are treated with compounds to prevent parasites from injuring the tender flesh of the oysters. These precious oysters are meticulously protected from every conceivable threat to ensure the finest pearls; however, typhoons, red tides of plankton and predators all take their toll before the pearls are even ready to be harvested. Once the oysters are brought back to shore the pearl farmers take inventory of the long-anticipated harvest.

Out of the millions of oysters nucleated every year, only a tiny fraction of them produce high grade pearls. On average, about half of the nucleated oysters do not even survive to bear pearls. Less than five percent of the survivors yield pearls of the ideal shape, lustre, and colour to be considered fine quality. The few pearls that make the cut are then cleaned, soaked and sorted.


The newest crop of pearls go through a series of gentle treatments to prepare them for jewellery. The pearls are first soaked for several days in a mild cleaning solution under intense fluorescent light to remove any deposits and odours they may have accumulated during their days in the ocean. The pearls are then bathed in a wooden vat of finely crushed walnut shells. The natural oils from the shells provide a soft and gentle polish without harming the integrity of the pearl’s surface. After they receive their luscious spa treatments, these pearls are painstakingly matched.


To assemble a single strand, workers must comb through thousands of pearls to find ones which match in size, shape, colour, lustre and surface quality. First, the pearls are poured into special sieves separating them into size groups. They are then sorted into increasingly smaller batches according to shape, body-colour, overtone and, quality. This precise and time-intensive work can take months to complete.


Upon completion of this process, the pearls are finally ready to be drilled and mounted. However, before a pearl is set into a piece of fine jewellery, it undergoes more rigorous screening processes. The matched lots are separated further into perfect pairs to create, a pair of earrings, or necklace. One by one, each pearl is individually drilled and strung onto temporary strands called loose hanks. These hanks are sold at auction.

Our technicians delicately open the shell of the pearl oyster to reveal its creation.

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