Pearl Luster

Pearls are made naturally from oysters. But the case of Tahitian pearls is a bit odd. A strange phenomenon, presents itself in the case of Tahitian pearls. Though it may sound strange, but the fact is that, Tahitian pearls are neither found in Tahiti nor are they all of the black variety as commonly believed. Tahitian pearls actually come in shades of brown, gray, green and purple. So black in just one color in which Tahitian pearls are found. But there are many others. Tahitian pearls are mostly big sized colorful gems that have gorgeous overtones and are endowed with an incredible luster of their own. These Tahitian pearls are basically cultured pearls but they look completely different than the other cultured variety which is the white Akoya pearl.

So how are pearls made? Pearls do not grow on trees nor are they manufactured in warehouses. They are found inside live oysters. When some foreign substance enters the oyster’s body, it tries to protect itself by secreting a substance called nacre. This substance covers the intruder and eventually multiple layers of nacre cover up the irritant and the resultant product is the pearl. In course of the time, oysters produce Tahitian pearls, the black-lipped oyster is around six to eight inches in diameter.

Tahiti, as we all know, is the largest island in French Polynesia but the pearl culturing farms are located in other remote islands in the territory that are accessible only by a sea plane or a boat. Actually, the blue lagoons of the Tuamotu Archipelago and Gambier islands are home to the pearl farms that cultivate and develop into Tahitian pearls. The shallow lagoons of these islands are bounded by coral reefs where the waters are nutrient rich, clean and calm. This helps a lot in furthering the culturing process. Here the pearls are found in a type of bivalve mollusk called black-lipped oyster that is native to French Polynesia.

The pearls that have been obtained in this fashion are called cultured pearls. Of course, the quality of cultured pearls depend a lot on the water body selected for cultivation, the nutrients available in it as well as various other factors like sweet or salt water, the depth at which the cultivation is practiced, etc. Since salt water is freely available in the sea, salt water oysters are easily cultivated in shallow basins or lagoons that are not very deep. Some sea-waters provide ideal cultivation and pearls obtained from such places are linked to the area and hence named after them.

Tahitian pearls are much in demand with jewelers and fashion designers all over the world. Since Tahitian pearls come in various sizes and colors, they make beautiful pendants, necklaces, rings, earrings and are widely used in jewelry worn by ladies while men’s items cover cuff links, tie pins and others.

Pearls are formed inside the shell of some type of bi-valve mollusks such as oysters when a tiny foreign substance gets stuck inside it. These pearls are known as natural pearls. And when the foreign substance is manually inserted into the oyster, the pearl so obtained is referred to as a cultured pearl. In response to the irritation caused by the entry, the oyster immediately starts depositing layers of calcium carbonate in the form of calcite, eventually producing the pearl.

There are basically two types of cultured pearls - they are:

• Freshwater pearls
• Saltwater pearls

Freshwater pearls are the ones that come from fresh water mussels or oysters. These are mostly produced in Japan, China and the United States. Backed by a wing of the United Nations, freshwater pearls are now also being cultivated in Bangladesh.

Freshwater pearls are cultivated in lakes and rivers and a single mussel can produce up to 50 pearls. Saltwater pearls are nucleated within a small organ called the Gonad, while freshwater mussels are nucleated in the mantle tissue itself. Each side of the bi-valve mussel can easily handle up to 30 nucleations at a time.

Freshwater pearls are a delight of designers as they come in a variety of shades such as…

White, black, pink, lavender, purple and tangerine

The shades depend on the type of mussel. Freshwater pearls are also available in many shapes, including rice, button, winged, oval and flake. Insertion of slices in the mantle plays a big part in determining the size and the shape of these freshwater pearls.

However, using non-nucleus insertion method, freshwater pearls can be raised in various shapes including round, semi-round, potato, rice, short rice, long rice, water drop, flat, twin face, quad face, bread and others. With the help of Bewa Slice Insertion techniques, pearls also appear in pipa shape, long or short stick, long or short slice. Nucleus Insertion technique makes these pearls look like square, rectangle, rhombus and other interesting contours.

As these pearls usually come in smaller sizes, new technology has been developed to increase the size of freshwater pearls. It involves “Additional Planting” which is an extension of the traditional cultivating process. This technology actually uses the suspended mussel that has been raised over 2 to 3 years, and selects the finest and continuing suspended cultivation for three or more years. The process, no doubt, takes longer time but the results are promising.

The success in freshwater pearls lies in the use of graft tissue and a nucleus. Usually, the graft tissue is a portion of the mantle which is a part of the mussel that produces the shell. When a portion of this mantle is grafted inside the body of the mussel, it lives by attaching itself on the wall of the organ where it is introduced. Once there, it begins to receive nutrition and function as a part of the mantle, secreting shell substances and coating the nucleus.

And this is how freshwater pearls or cultured pearls are produced.

Believe it or not, the word ‘Mother of Pearl’ is not a misnomer. It is just an innocuous oyster or rather the secretion that it produces in the form of calcite that gives birth to a pearl through a biological process.

An oyster has two shells that are connected by an elastic tissue like substance allowing it to open and close at will. The shells are mostly kept open for nourishment. Inside, the oyster has another tissue like substance called mantle that secrets a kind of fluid called nacre. When a tiny foreign substance gets engrossed within the oyster by chance, causing irritation, the mantle immediately starts covering the irritant with layer upon layers of nacre and eventually forms the pearl.

This, of course is a natural pearl. Taking the cue from nature’s school, pearl farmers manually insert such an irritant into the tissue of an oyster or mollusk, inducing it to create a pearl and these pearls are popularly known as cultured pearls.

During the late 19th and early 20th century, Japanese researchers, notably Mr. K. Mikimoto perfected the method of cultivating cultured pearls. And today, cultured pearls are mass produced since the chance element is eliminated. Pearl farmers can obtain as many pearls as they need under controlled conditions.

While natural pearls can have deformities and/or malformations, cultured pearls can be schooled for elegance and appearance. Today the technology has developed to such an extent that the shape, design, color and overall appearance of cultured pearls can be pre-determined by the pearl farmer, matching market stipulations. Now the oysters can also be monitored till the pearls are fully formed as per requirement, ensuring their nourishment, health and survival so that an unlimited harvest of quality cultured pearls are assured. As a direct result of these achievements, cultured pearls have become much more affordable these days and are not something that only the super rich can afford.

A few instances of successful farming of cultured pearls:

1. Tahitian Pearls - In the cool, quiet salt water islands in the French Polynesia, namely the blue lagoons of the Tuamotu Archipelago and Gambier islands, far away into the sea, approachable only through sea-planes and boats, farmers are involved in producing black cultured pearls that are in demand in the world market. Here the black-lipped oysters having rainbow colored mantles live up to an unbelievable 30 years or more and has girths up to a foot.
2. Akoya Pearls - Also grown in ocean salt waters, Akoya pearls are the most popular cultured pearls in the world, famous for their shape, beauty and high luster. Though smaller in size, no other type of pearl can match the luminous luster of an Akoya. Incidentally, Akoya pearls were the first pearls to be cultured in the early 20th century, making pearl jewelry affordable.

Cultured pearls can often be distinguished from natural pearls through the use of X-ray that reveals the inner nucleus of the pearl.