Understanding
Cultured Pearls
MAN AND NATURE CONSPIRE
Until 1893, the only pearls available were those that were naturally made when an irritant strayed into a pearl. So rare was this occurrence that pearls were the exclusive domain of royals in the West, and Emperors and Empresses in the East. Like silk fabric, pearls were restricted, if not by law, then by price and availability, from virtually all people except the aristocracy.

However, in Japan a young man with an entrepreneurial spirit named Mikimoto Kōkichi believed so strongly that every woman deserved and should be able to have a pearl that he dedicated his life to pearl cultivation. The son of a noodle shop owner, Mikimoto dropped out of school to sell vegetables to help support the family. Yet he became so fascinated by the bounty of pearl divers at a nearby port that by the age of 20 he was judging a pearl exhibition. His curiosity was sparked by the misshapen forms of these natural pearls and soon he became focused on creating pearls that would be round and blemish-free.

Relying on what had already been learned and theorized in the West as well as his own experiments, in the late 1800’s Mikimoto made numerous attempts to culture, that is, artificially stimulate, an oyster to make a pearl.

At that time it was strongly believed that inserting a nucleus into the oyster would result in a pearl. Mikimoto was the first to successfully achieve that dream, using a refinement to the original nucleus-based methodology. He was the first to successfully culture a pearl by adding a tiny piece of the living mantle (the oyster’s soft body sac) along with the nucleus. This became the basis of his pearl farming empire which quickly flourished along Japan’s coast.

Mikimoto’s cultured pearls showed that the oyster grew sac mantle tissue to encase the nucleus. The mantle then proceeded to secret nacre over the sac. This substance is essentially the same as the mother of pearl that the oyster secretes to line the inside of its shell. Nacre is calcium carbonate, and over time, successive layers are added to the growing pearl's surface.
AMA women divers.
MIKIMOTO, the first to culture pearls.
THE MIKIMOTO STORY
The Mikimoto flagship store in New York City.
If viewed in cross-section, the inside of a cultured pearl will actually show these distinct layers, not unlike the rings that are seen on a tree cross-section. With increased incubation time, more layers are deposited and with each successive layer, the pearl’s luster increases. Mikimoto found that at least two years were required before the oyster produced sufficient nacre to give pearls exquisite luster. These pearls were only cultivated in cold, salt water and they became known as Akoya pearls. Their size could be as large as 8mm - 9mm in diameter; their shape was round and near-round.

For decades Mikimoto farms dominated the world’s pearl production. The pearl jewelry manufacturing company that bears his name is still recognized for outstanding quality and design.
WARM PACIFIC OCEAN WATERS
A strand showing the naturally-occurring color variation of cultured South Sea pearls.
In contrast to the cold waters off Japan, the relatively warm waters off Tahiti, Australia and the Philippines produced much larger-sized pearls with remarkable coloration based on location.

The South Seas produce exquisite white pearls with phenomenal overtones of pinks, golds and blues. Tahitian pearls (which are no longer referred to as “Black Pearls”) vary from shades of grey to peacock to pistachio; and many pearls originating from pearl farms located in the Philippines glow with a golden sheen.

Today, one of the most perfect pearls in the world is privately owned, and valued at approximately 5 million dollars. This white South Sea pearl was cultivated off the Australian coast and measures 21mm of blemish-free nacre.
THE LARGEST OF ALL PEARLS
FRESHWATER CULTIVATION

The freshwater varieties of cultured pearls originated with the Chinese, who have now become the most dominant pearl farmers in the world. Their techniques have allowed for experimentation with shapes, sizes and post-cultivation color development. The success of freshwater cultivation was based on the selection of a different bi-valve as host for the incubation process. The oysters used for salt water Akoya pearls were substituted with mussels. The resulting methodology for successfully grafting the nuclei and tiny pieces of mantle into the mussels required less technical skill compared to the Akoyas, and thus many more workers could be involved to assure rapid expansion of the pearl farming movement in China.

The naturally occurring colors of freshwater cultured pearls range from white to cream to soft pink and peach tones. All other colors have had their colors developed after they are extracted from the mussels using dye and laser processes. Now, pearls in burgundy, lime green, dark pink and even deep blues are available.

Pearls are classified by shape, as either round or baroque, with the latter encompassing a variety of irregular yet definitely elegant forms. By using nuclei that vary from the traditional round globe, pearls are now cultured as flat coins, and square and rectangular tiles. Hearts, crosses and other forms are all now possible,and are still based on the placement of their respective shape of nuclei into the mussel. Another class of pearls called Keshi do not have nuclei, and are composed just of layers of nacre. These Keshi pearls were discovered after the nucleated pearls were removed, and so are called second harvest pearls. Keshi are formed during the regular cultivation process. It seems that the mussels reject and expel some nuclei. Still nacre production has been stimulated and the resulting shapes are concave flakes and finger-like extensions of nacre.

Natural color Keshi pearls.

(Below) Coin-shaped pearls using disc-shaped nucleii.

 

Potato-shaped, near round (left).
SIMULATED PEARLS
Throughout the history of pearl cultivation, other companies have chosen to simulate pearl beauty using manufacturing methods. Glass beads are most frequently used. Another method coats a hollow core with fish scales before coloring. One of the main distinctions between these faux versions is that the wearer never really experiences the natural weight of cultured pearls.

SHELL PEARLS offer a remarkable alternative.
This type of simulated pearl comes closest to the real ones. The mother of pearl that lines shells is used in the laboratory to manufacture the core. Because mother of pearl is essentially the same as the nacre that the oyster lays down to form a pearl, these pearls have essentially the same weight, and so they feel like a cultured pearl strand. The indicator that shell pearls are simulated is that their shape is too perfectly round compared to those pearls that nature makes. With modern coating techniques, the color and luster can be adjusted to mimic those produced by oyster cultivation. These coatings also prevent shell pearls from picking up fragrance and make-up, which can be a problem with cultured pearls.

Because the process for making shell pearls occurs outside of the oyster, much of the time and expense needed to produce them makes for remarkable pricing. What it takes to make a matched strand of oyster-cultivated South Seas that sell for $20,000 - $30,000 can be simulated for a mere few hundred dollars using shell pearls.

Shell pearls provide stunning alternatives for those travelling women who would prefer to leave their prized cultured necklaces and bracelets at home, yet want to make an impression with their jewelry while out of town.
Shell pearls can closely resemble South Seas pearls and are excellent for designs reminiscent of Chanel.