History of the pearl farming
From the first centuries AD, the Chinese mastered the creation of figurines covered with nacre extracted from fresh water mussels. We learnt thanks to written documents that first Arab people cultivated and farmed pearls. There have been many attempts to farm pearls in Europe and the rest of the world starting from the 16th century. However history mainly remembers the name of the Japanese Kokichi Mikimoto who came up with the marine cultured pearls as we know it nowadays, and registered a patent in the early 20th century.
While there were many attempts to farm pearls from the black lip pearl oyster during the first half of the 20th century in the South Pacific Ocean, French Polynesia started experimenting pearl culture during the sixties. Dr Jean-Marie Domard, a French vet, assured that the environment of the lagoons and seas around Polynesia met every necessary condition in order to farm and cultivate pearls. After successful pilot tests, a few years later, breaking ground farms set up on the islands of Manihi, Marutea and Mangareva and gave birth to what has grown up to be the second greatest business in Polynesia.
Development of a natural pearl
Pearls grow up inside mollusks producing nacre (oysters, mussels, clams, abalones, etc…), which live either in salt or fresh water. A natural pearl is born from the accidental lesion of the mantle, which heals by covering with layers of nacre, creating a pearl sac. This pearl sac is crucial, for it contains the cells to secrete nacre. Nacre, also known as aragonite, consists of calcium carbonate crystals and a protein named conchiolin. After a few years, the pearl has grown up inside the pearl sac.
Development of a cultured pearl
The mechanism somewhat differs. It needs a nacre support, called the nucleus, a perfectly spherical marble from a fresh water mussel. Used since the beginning of pearl farming, these mussels features a nacre shell thick enough and with a consistence very close to nacre from marine pearl oysters. This nucleus will be inserted into a specific organ of the oyster, a very large appendix whose functions are not well-known yet. (Most of the time it is improperly called a gonad.)
For convenience, we call this organ the pearl pocket. The insertion of the nucleus requires to use a scalpel for an incision, carried out with precision for the positioning of the nucleus into the pearl pocket has a great influence on the pearl quality. In addition to the nucleus, a graft is set up in the pearl pocket, if possible joined on to the nucleus. A graft is the common word used to name the mantle part from an oyster sacrificed for this purpose. This graft is the roof of the pearl sac which will eventually cover the whole nucleus with layers of nacre, as it is the case in the development of a natural pearl.
Natural pearls vs Cultured pearls
Actually, cultured pearls and natural pearls look alike, since they both grow up inside a pearl oyster. The main difference comes from the necessary human intervention and from the nacre nucleus for the cultured pearl. The mineralization process is like the original, as well as the produced nacre.
In such conditions, it is really hard to make a distinction between a cultured pearl and a natural pearl. X rays and the drill hole examination are the best-known means. However, most of the pearls on the market nowadays are cultured pearl. Although the odds of creating a perfect cultured pearl are 1 or 2 percent, the ones of finding a natural pearl are 1 out of 15.000, and since fishing most pearl oysters is banned worldwide they are even more uncommon.
Cultured pearls worldwide
Pearls form inside mollusks living in fresh or salt water. Marine pearls are the most sought-after, for their diversity, their luster, their iridescence, as well as for their thickness or the quality of their nacre. There are more than 70 pearl oyster species worldwide. The main ones belong to the Pinctada genus. Three types of pearl oysters, “pintadines”, are internationally-known for their ability to produce outstanding cultured pearls.
Pinctada fucata or Pinctada martensii, also known as white lip pearl oyster or Akoya oyster, is farmed in Japan, China and Korea. This gorgeous pearl oyster creates white pearls, also called Akoya pearls, which represents the greatest quantity of traded farmed marine pearls.
Pinctada maxima, better known as silver lip or golden lip pearl oyster, produces exceptionally large pearls, whose colors vary between white, silver and gold. They are mainly farmed in Australia and in Indonesia.
Pinctada margaritifera called black lip pearl oyster, produces rare and magnificent pearls. Living in the South of the Pacific Ocean, they abound round the islands and atolls of French Polynesia. They are famous for their opalescent intern shell, tinted with black and green shines. Pearls feature an incredible range of natural colors, each one as sparkling as sparkling can be.