The mystery of the pearl's birth
In nature, the pearl is born in an unremarkable-looking oyster that lives in warm sea waters (Persian Gulf, Tahiti, Australia, Japan, Thailand etc.). Pearl formation is a kind of the mollusk's protective reaction to a foreign body caught in its shells. The mollusk envelops the irritant with a layer of nacre, thus isolating it. Over time, layer upon layer, a pearl is formed.
Under natural conditions, this process is extremely rare and lasts for years. Just imagine, it takes a mollusk nearly 20 years to form a pearl with a diameter of 5 mm! It is not surprising that for centuries only members of royal families, clergymen and VIPs had the right to wear pearl jewellery.
So what are naturally cultured pearls?
In the early 20th century a Japanese pearl fisherman discovered the secret of pearl's birth and introduced a method for growing them. It turned out that a foreign body could be forcibly introduced into a mature oyster to form a pearl after a few years. Such pearls are called cultured pearls and are strictly controlled in terms of quality. The layer of nacre must be of a certain thickness.
But even after this method appeared, pearls did not become a mass product. Despite all human efforts, the final decision to give birth to a pearl lies in nature; the mother oyster may simply reject the foreign body or even die, unable to tolerate the invasion. Sensitive to the slightest changes in sea water composition and temperature, oysters have become victims of global warming and air pollution.
The Yamagiwa experts take care of the oysters with a truly Japanese zeal: they monitor the currents and water temperature, and periodically clean the shells from impurities.
The pearls they harvest must be sorted. In nature, no two pearls are exactly alike, so sorting pearls is an extremely difficult and time-consuming process. Pearls are grouped by size, shape, colour, and brightness of the mother-of-pearl layer, so each pearl shall be shifted many, many times.
After sorting, a hole is drilled into each pearl, as even the slightest mistake can damage the stone. It is also important to make the hole exactly in the centre of the pearl, as even the slightest asymmetry may spoil the look of the piece.
After that, it is the next stage of selecting identical pearls to make the piece. This is an even more painstaking procedure than sorting; the jewelers must select the most similar pairs of gems from a group of pearls already sorted by size, shape, colour and brightness, which means they are extremely similar to one another. Only a skilled craftsman with long years of experience can skillfully select pearls for a necklace, earrings or any other piece of jewellery. In order to select 47 pearls exactly alike for a 16-inch necklace, for example, it may be necessary to look through more than 10,000 stones.