Few are the most attractive gems of natural pearls that, throughout history, have had such a special place in the hierarchy of objects used for personal ornamentation. The discovery of the decorative beauty of pearls is lost in the mists of prehistory; perhaps they were the first gems known to man. The first discoverers of pearls could have been, at the dawn of humanity on Earth, the inhabitants of the sea coasts or of the rivers that fed on pearl-producing mollusks.
The birth of a pearl is a truly miraculous event. Unlike stones or precious metals, which must be extracted from the earth, pearls are produced from oysters or better from “pearl-like mollusks” that live in the deep sea. Precious stones must be cut and polished to bring out their beauty. But pearls do not need this complementary process. They are born from these mollusks with a natural iridescence, a shine and a soft intrinsic brightness that no other gem in the world possesses.
The formation of the pearl occurs when on the seabed elements foreign to the mollusk penetrate inside the epithelium, creating an action of strong disturbance. In short, the pearl is formed around a foreign body (grain of sand, parasite, marine larva, fragment of shell) entered into the mollusc; this intrusion produces a strong reaction in the animal which, failing to expel it, begins an isolation process by secreting a smooth and hard crystalline substance, called a pearly substance. As long as the foreign body remains in the mantle (the skin flap that lies between the shell and the body of the animal), the pearl oyster continues to secrete around it the mother-of-pearl substance, layer upon layer. After a few years, the result will be that of a beautiful and shining gem that we will call a pearl.
The difference between a natural pearl and a cultivated pearl is very simple: in the case of the natural pearl, the foreign object enters the shell of the mollusk in a completely random manner, while, in the case of cultivated pearl, it is surgically introduced into the mollusk from ‘man.
The fundamental name in the history of the cultivated pearl is certainly that of Kokichi Mikimoto, who dedicated all his long life to the study of shellfish and the pearl trade: his successes allowed Japan to establish a market monopoly. In 1888 Mikimoto started the first breeding of pearl-producing mollusks, obtaining the prototype of a cultivated pearl, and, in fact, created and organized the cultivated pearl industry.
However, the first to obtain a spherical cultured pearl was in 1903 the carpenter worker Tatsuhei Mise and in 1907 the zoologist Tokichi Nishikawa employed at the Ministry of Fisheries. They combined their experience by perfecting the method based on the insertion of a spherical nucleus of mother-of-pearl and a fragment of epithelial tissue, still used, and patented in 1908.
A few years later, the first cultivated pearls arrived in large quantities on world markets creating real turmoil. Indeed, it was very difficult to distinguish them from natural pearls and their substantial price difference caused panic among the operators in the sector. The market found its equilibrium only after the introduction of fast and safe methods to distinguish them.
Cultured pearls are divided into:
1) AKOYA: Japanese cultivated pearls that take their name from the mollusk that produces them. These are the shells used for the first experiments in the cultivation of pearls.
2) WHITE SOUTH SEAS: pearls grown in Australia, Myanmar, Indonesia, and the Philippines. They are produced from large tropical or semi-tropical mollusks belonging to the “Pinctada maxima” family with white-gold lips. Generally, they measure from 10 to 18 millimeters.
3) BLACKS OF THE SOUTH SEAS: pearls cultivated in French Polynesia (Tahiti) produced by large pearl oysters with black lips.
4) FRESHWATER: they are grown mainly in the rivers in China. Each shell easily produces a large number of small and medium-sized pearls. Their low cost makes them suitable for very affordable jewelry or for good jewelry.
Chinese freshwater cultured pearls are also produced without the nucleus, ie fragments of epithelial tissue and not the mother-of-pearl sphere are inserted into the mollusk. It is very important to clarify that this procedure is always to be considered a human intervention and therefore the pearl that will emerge will be a cultured freshwater pearl of Chinese origin. Some jewelers, on the other hand, sell these pearls for natural, just because they have no core.
The reality is that natural pearls, the real ones, are so rare that they can now be found almost only in antique jewels, and the strings of natural pearls if they were to be found, would cost mind-boggling figures.