The Pearl is a spherical structure more or less regular, consisting of calcium carbonate deposited in layers concentric from living tissues of some mollusks.
It is formed when a foreign body penetrates the soft mantle of the mollusc, causing an irritation of the tissues. As a reaction to the irritation of the animal, he holds the foreign body of thin layers of concentric of nacre or mother-of-pearl , which in the course of time will lead to the formation of a pearl
The beads are divided into 2 types :
Natural Pearls in which the foreign body that generates the pearl penetrates accidentally inside the clam
The Cultured Pearls in which the foreign body is inserted from the man.
Today, 99% of the market consists of cultured pearls and the few natural pearls sold are found accidentally by fishermen.
Akoya pearls or Japanese
Pinctada fucata martensii
the Oyster is cultivated within the nurseries in sea water for a period that can range from 10 to 24 months. This is a clam perlifero not very productive that accepts l’graft a single nucleus at a time, and, in the course of his life, bears only a cultivation. It is a small animal, capable of producing cultured pearls diameter tended to be reduced, but by the characteristics of exceptional.
The main producer of this variety of pearls is of course in Japan, but there are crops in China, Vietnam, Korea, and Thailand.
The size of Akoya pearls ranging from 2mm to 10mm, and their main feature is the sphericity. In fact, the percentage of pearls spherical almost 80% of the crop.
In addition, the surface of these beads has a few defects and is characterized by a remarkable shine, with a base colour of white, but that can have an affect gray, silver, pink or champagne.
Features Shape, Size, Color, Brightness, and Degree of homogeneity they become, therefore, the parameters of the classification of beads that allow the division into categories and to facilitate marketing.
The raw state of the Akoya pearls are generally of a cream color, yellow, or green. After a wash carried out with particular substances, of which each company manufacturer preserves the technique secretly, are bleached and assume dyed white silver or pink champagne, becoming more uniform in color.
Pearls South Sea or Australian
The first phase of the cultivation of pearls, South Sea fishing is, in fact, the Pinctada Maxima is not raised, but rather drawn from divers, as it lives at depths that can reach up to 100m. After the mussels are cleaned and selected, and only then proceed to the graft.
The Pinctada Maxima is a body, which is very delicate and its cultivation is characterized by a high percentage of mortality, that gets to tap as much as 80% of the specimens.
The cultivation period lasts about 2 years.
The collection takes place in the winter months because the temperature is lower the secretion of measurement is more slow and uniform, and this leads to a higher sheen
The Pearls of the South Seas are easily identifiable by their size, which generally varies between 9 and 17 mm. They have a spherical bulge of mother-of-pearl coated with a layer thickness thick enough and compact the pearls 15mm comes in at about 4mm.
From a chromatic point of view Pearls of the South Seas, distinguished according to the mollusk that produces them. In fact, there are two variety of the Pinctada Maxima, the first called the oyster to her lips and silver produces clear beads ranging from silver white to pinkish white, the second variety is called the oyster to her lips, golden produces pearls with hints of champagne or pale yellow.
These beads unlike the Akoya pearls also have a superb variety of shapes that allow for classification:
Round (perfectly spherical)
Semi-Round (almost spherical)
Oval (elongated, more or less oval)
Button (spherical mashed)
Place of cultivation:
The south sea Pearls are cultured Primarily in Australia, and specifically in the north-western part of the continent, in a remote area which is about 200km from the major urban center, and that, therefore, does not suffer from the effects of pollution.
The other producing countries, but with the odds decidedly more low, are Indonesia, the Philippines and Vietnam.
Unlike australia, the cultivation process begins from the collection of larvae of the oyster in the center of the lagoons, making them secure on the supports properly installed. The young oysters are then collected when they reach the size of about 2 cm, and after selection, are raised in the nursery for about 3 years to reach the size required to implant the nucleus of the mother-of-pearl. Later on, the oysters are placed again in the lagoon for not less than 18 months.
Despite the attention and the care, less than half of the molluscs will yield one or, rarely, two pearls
The main feature of the Pearls of Tahiti is definitely the colour, indeed, they are the only pearls that are dark and have a kaleidoscope of colours from deep Black through various shades of gray comes up to the teal or blue/purple. The size of these pearls approaching those of the australian pearls ranging from 8 to 16mm.
Also, the Pearls in Tahiti are a remarkable variety of forms that is very similar to that of the australian.
Place Of cultivation:
As the name suggests, these pearls are cultivated in the island of Tahiti, and more in general, in the archipelagos of Polynesia.
Fresh Water pearls
The cultured pearls fresh water come to life thanks to a technique different from that used for the cultivation of saltwater pearls. In fact, to trigger the production of pearls, Fresh water, in the mantle of the oyster is placed a fragment of the epithelium of another oyster, and not a group of mother-of-pearl as it happens with other varieties of cultured pearls. Inside the cloak grafted, it will form a pearl anucleata, which is devoid of nucleus and consisting entirely of layer thickness. Unlike the marine molluscs those of fresh water, after receiving the first plant can continue to produce beads, for two or three consecutive cycles
The main feature of the pearls Fresh Water is the unlimited variety of forms, the most common are irregular. The round shape is far less frequent, because there is no nucleus, it is more difficult to get an accretion perfectly spherical.
The size of the pearl of Fresh Water is, on average, larger than Akoya and goes from 2 to 13mm, while with regard To the colours they come in a variety ranging from white to purple through the shades of pink.
The area of cultivation:
the fresh water pearls are produced mainly in China, but there are productions in Japan, and the united States.