Tuesday, May 17, 2011

Pearl

How pearls produced?

Although there is still the pearl of the natural search efforts, but most of the pearls that are in the market today is the result of human engineering. Engineering was discovered by a Japanese, Mikimoto at the beginning of last century. Given such a potential so that the Japanese pearls keep this secret until the late 80's. So do not be surprised if the Japanese develop their business in other countries in the Pacific and Indian Ocean region such as Indonesia to continue to use the technician. However, Indonesia as a potential area of ​​cultivation for almost all types of pearl oysters has become one of the major pearl producing countries of the world along with Japan, China and Australia. 


Form of the engineering is known as grafting or seeding and implantation,by inserting the core (nucleus) together with a piece of mantle organs (sliced ​​meat of other pearl oysters, known by the name 'saibo') into pearl oysters. Mantle organ was taken by another individual pearl oysters and act as a donor. Based on research, good donor selection will determine the quality of pearls produced mainly in terms of color, shape and luster of pearls. The core and mantle wedge is placed inside the oyster gonads after earlier is made a small incision in the gonad wall. Sliced ​​meat coat will form pockets of pearl (pearl sac) and will be producing nacre. This process is known as bio-mineralization, similar to the process of bone formation in humans and other vertebrates. Nacre is part of the shiny surface of the pearl or the wall is also a shining part in shellfish. On the inside of the shell, nacre termed as the Mother of Pearl (mother of pearl), while the nacre is inherent in the core called the pearl. The quality of produced nacre determines overall quality pearls. 


The process of inserting a small part of a series of long cultivation process since the determination of the location of cultivation until the post-harvest handling. The principle of embedding process is based on how the naturally formed pearl shells which will wrap the irritant that can not be avoided with nacre. The working principle is the same when the scallop shell is damaged, they will immediately close the hole with nacre, which prevents its soft body is exposed. But so far no evidence that natural pearls are formed by the influx of sand grains into the body shell. Strong assumptions that support the formation of nacre layer is the existence of viruses such as those found in several types of cultured pearl oysters. 


The process of making pearls 


Natural pearls

In nature, pearls are formed due to the irritant into the oyster pearl coat. The phenomenon of the irritant is often also interpreted by the entry of sand or solid material into the mantle then this object will be wrapped so that the pearl nacre can be produced. Theoretically, Elisabeth Strack (depth contained in the book Pearls in 2006) describes the formation of natural pearls is divided into two major parts, formed by the irritant and the entry of solid particles in the mantle of mollusks. In principle, the pearl is formed because of the mantle epithelium into the mantle cavity. Part of this mantle epithelium served out / form nacre on the inside of the shell as well as forming a whole shell. Theory irritant revealed that at some point the tip of the oyster mantle eaten by fish, this is possible because the shells will open a shell and stuck out his coat to absorb the food. When her coat off, the crumb epithelium enter the mantle cavity. Theory irritant could have also revealed that pearls are formed due to the inclusion of a worm that usually occupy the mollusk at the time of its development and then move on to other organisms. This worm is destructive and entered the mantle cavity. This worm accidentally took part in the surface epithelium with her coat. When the worms die in the mantle cavity, then the worm will be covered by the epithelium, forming the pearl sac and eventually forming a pearl. Even if the worms can escape, then epithelium that remain in the mantel cavity will form the pearl after pearl pockets is formed. While the latter theory is the inclusion of solid particles into the mantle cavity. Solid particles can be trapped in the body shells due to encouragement of water. When these shells can not remove it, even this particle could have entered the mantle cavity. When he entered, epithelium also went with it. Epithelium is finally wrapped up the solid particles forming the pearl sac. These pearl sacs eventually will form nacre to these solid particles. However, so far no scientific evidence that supports the theory of the entry of sand into a pearl oyster mantle, although this theory has long understood. Of the few natural pearls are dissected, showing that the pearl is not a core part of solid particles. 

Cultured pearls
Before making process, pearl oysters in advance already undergone a process called weakening (making pearl become weak). This process is usually from 2 weeks to a month depending on the type of pearl oysters. This process meant that pearl oysters will be experiencing stress and entered the reproductive phase quickly so that if surgery process was performed its gonad have been empty. When the gonad is fully charged then the operations are difficult and even more have failed. This weakening process can by closing pearl shell with a porous gloves so small that filtered food particles or even a pearl shells were stacked together and then wrapped with a small porous gloves. In this condition, pearl oysters can still survive even though the food in larger particles is no more. After this process, pearl oysters raised to the ground (when the operation carried out on land) and undergo a process of continued weakening in the tank. They are stacked together so that they became weak due to food consumption and low oxygen. If surgery is performed without this process, pearl oysters are still very strong to kick out the nucleus is inserted into it's gonad. Even for the largest bivalve species P. Maxima, they are very strong muscles if you do not pass through the process of weakening so that the shell is very hard to open. At certain times of the water removed from the tanks and forced the oyster to open its shell. When clams open the peg shell,booster is inserted between the two shells of oysters so that it is ready for surgery. By the time without water,while the clam will open the shell, its mantel will be drawn into its coat. This process will facilitate the activities of pegging because when covered with water, clam will open a shell, but the edges will be closed by the coat, as a result, if the booster process is done,the peg will hurt the clam mantle. 


Cultured pearls is using the principle of formation of natural pearls with a nucleus as the basis for the formation of pearls. A trained technician will prepare the pearl nucleus is usually round and come from other shells and pieces of mantle or saibo that taken from another pearl oyster. The selection of donors is considering color and quality of Mother of Pearl nacre (present in the side of the shell). Initially the technicians will kill mussels donors carefully so as not to touch its coat. When the coat was touched, it will wrinkled due to reaction from the clams. Killing donor shells done by inserting a knife between the shell and cut the muscle of the scallop aduktor donor. When split, clams were taken up quite dead, so when the coat is touched she did not react anymore. Next, the mantle is attached to the second shell is cut and its mantle is cut again into small pieces (approximately 3 x 3 mm). That coat section is prepared for insertion is called saibo, so that donors also called clam shells saibo. When the insertion operation, the wedge
already have been placed between the two shells. Clam receiver is placed in such a way as to be easily operated. Shell opener has a duty to open the shell wide open, then the technician will cut a thin section between the gonads and legs of the shells as a place of entry of the core and saibo.The core size is selected in accordance with the size of the gonads. After that core is entered into the gonad and then followed with a single sheet saibo. Saibo sheets are placed in such a way as to stick to the core with the ectoderm (which contains the nacre-producing epithelium) facing the core. Because if the reverse then chances are very small round pearl is formed. After that clams placed into a basket or a panel, and finally returned to the sea. Surgical technique and postoperative is vary each firm pearls. In principle, by applying certain techniques, pearl oysters will not"kick"out of the inserted core and eventually can produce good quality round pearls. The selection process for the recipient oyster / pearl-producing mussels also consider the age and period reproduction. When the shells in the reproductive period then its gonad will be full, so it is considered not suitable for embedded cores. The ability of the technician will determine the quality of pearls which is produced later.

Source: http://mutiara-mutiara.blogspot.com/2007/01/bagaimana-mutiara-dihasilkan.html

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