Ancient stories tell of how the Arabs had a superstition that pearls are dewdrops filled with moonlight, which fall into the sea and are swallowed by the oysters, then turn from liquid to solid form. Certainly these satiny spheres do seem to have the soft gleam of moonlight, but their origin is quite and entirely earthly, and much more wonderful than any legend could invent.

Personally, I love both the old legends and the nitty gritty reality of a pearl. One of my greatest pleasures is buying natural pearl necklaces filled with moonlight each time I visit my son in Hong Kong. It's the one luxury I allow myself, and it is a luxury. At this point in life, I seldom dress up enough to wear a strand of pearls -- but when I do -- I have a variety to choose from. I think the soft gleam of the pearl is just flattering to any woman.

Natural pearls are found inside the shells of certain kinds of molluscs, such as pearl oysters, fresh-water mussels, and others.

The most valuable pearls come from the pearl oysters that grow in the warm waters of the Persian Gulf, the Red Sea, and off the Northern coast of Australia (including some islands in the Pacific).

In the past, and sometimes now, men had to dive down many feet below the surface of the sea to gather the oysters, and by no means did all of the oysters they found contain pearls.

Actually, comparatively few of them had peals of great value. Today, of course, the vast majority of pearls sold are farmed commercially.

Lets See How Pearls Come to be Inside the Oyster Shell

We've all seen seashells with lovely, glistening linings of pearl. This pearly lining is made of nacre, a substance manufactured by the creatures that live in the shells, from chemical drawn from the water surrounding them.

This pearl shell is what we call mother-of-pearl, and many things have and always will be made from it, such as buttons, handles for knives, beautiful inlay work on furnishings and other useful and decorative articles.

Sometimes a tiny grain of sand, or perhaps a little parasite, works its way into the shell of a mollusk, and gets caught in the soft mantle, or membrane, that lies between the shell and the creature inside.

This irritates the tender membrane, and in order to stop the irritation, the mollusk begins to coat the intruder with thin layers of nacre.

Day after day and year after year, the shining nacre is deposited on the nucleus, or object in the center, until the pearl sometimes grows quite large.

As the mollusk deposits the nacre, its muscles expand and contract in an effort to get rid of the object entirely.

This it can not do, but the movement has the effect of rolling the object around, so that the nacre is smoothed on in even layers and the growing pearl keeps a round shape. This is the way that the perfectly round pearls, which are the most valued, grow.

Not all peals are perfectly round. Some are irregular in shape, and these are called baroque pearls. The most beautiful baroque pearls are the pear-shaped ones. Others are domed-shaped, like a ball that has been cut in two. This happens when the growing pearl has become attached to the shell.

Sometimes a parasite will bore through the shell and the mollusc will try to protect itself by covering the invader with nacre, creating what is called a blister pearl, round and rather flat, with a hollow in the center where it covered the parasite.

These oddly shaped pearls are often made into beautiful pendants, brooches, rings and other jewels, but they are not so valuable as the round pearls.

The chemical substance that the mollusc uses to make nacre is a form of calcium carbonate called aragonite. Limestone and marble are also made of calcium carbonate, but that is a slightly different kind known as calcite. The aragonite that makes nacre is mixed with a sort of gummy substance produced by the mollusc itself.

Pearls come in many different colors, but the most valued are rose, cram, white, and black. The color of a pearl is the same as that of the nacreous lining of the shell, and this is determined by a number of things, among them the health of the mollusc, the temperature of the water, and the kinds of minerals and chemicals that the water contains.

The lovely shimmering glow of the peral is caused by the light rays which are broken up by the layers of nacre as the light tries to find its way through. These different layers are of different thickness. The thinner they are, the greater the lustre of the pearl.

I once was friends with a Greek rope maker that I knew simply as Old Man Papadopoulos. He'd traveled a bit during his time as a sailor, and one of the many stories he told me were about Bahrain pearls. The oysters we eat sometimes contain pearls, but they are not the valuable kind. In the past, the finest pearls come from the Persian Gulf, in the waters near the island of Bahrain.

They are still considered the finest pearls that can be bought and it is illegal for cultured pearls to be sold or farmed there. In the past, the season for Bahrain peal divers began in the middle of May, when the waters grow warm and it lasted until the end of September.

On the day when the season was proclaimed open by the ruler of Bahrein, a fleet of several hundred boats, called dhows, gathered in the harbor to set off for the pearling banks -- the shoals and ledges out in the gulf.

The dhows had oars and sails, and the men row them until they reach the open water outside the harbor, singing the ancient song of the pearl fishers as they row.

When the dhows reach the banks, the divers began, and was done in much the same way as in the time of Marco Polo, over seven hundred years ago. The divers worked in pairs, one of them diving while the other stayed on guard in the boat and to help him come up to the surface.

Each diver wore a clip like a clothespin to keep the water from getting up his nose. He wore no clothing of any sort, but his fingers and his big toes were encased in leather. This helped him to grip the sea bottom and protected his hands when he wrenched the shells from the rocks to which they were attached.

The diver did not really dive, he climbed down a rope to the bottom, carry a heavy stone to give him weight. When he reached the bottom, he quickly gathered as many shells as he could and put them in a string bag which was fastened around his neck.

A minute and a half was usually all the time that a diver could stay under the water. Then, he twitched the rope to signal his partner, and was pulled up to the boat. A good diver was said to have been able to go down as many as thirty times in one day.

Thinking on that story, I can only imagine what a thrilling moment it was when a shell was opened. Who knows -- probably a perfect pearl of fabulous value may have been found from time-to-time inside! I can picture the divers all sharing this suspense, for their livelihood depended upon the profits from the whole catch.

In almost all pearling areas, the divers were paid a share in the profits instead of wages. Around Bahrien and in other places this system was said to be very fair and well regulated, but that was not the case elsewhere in the world.

Pearls are sorted according to size and shape, and sold to dealers. In the Persian Gulf and the Indian Ocean, most of the pearls are sent to India, where the great pearl market is.

Here since ancient times, they are washed and polished, and the ones which are to be used in necklaces are drilled by hand, according to a three thousand years old method that requires great skill and delicacy.

A necklace of real pearls costs thousands and sometimes hundred of thousands of dollars. However, it takes years to collect the pearls that go into such pearl necklaces, unlike with cultured pearls.

The pearls must be perfect in shape and quality and exactly the same in size and color. Shorter strands of pearls are usually graduated in size. That is, the pearls at each end, near the clasp, are small, and each succeeding pearl is a little larger. The biggest one being the exact center of the string.

It is believed that the pearl was the first gem to be known to man, and you'll find it mentioned in the oldest writings. Many legends and stories have been told about the pearl during its long history. In many countries pearls have been prized above all other gems. Naturally, there have been many efforts to imitate the pearl.

Most of the artificial pearls are made by coating either the inside or the outside of a glass bead with a pearly substance.

The cultured pearl, of course, is not a natural growth. As far back as the thirteenth century, the Chinese knew that pearls could be grown by putting a piece of mother-of-pearl or freshwater mussel or some other foreign substance inside the shell of a river mollusc. The mollusc would at once start covering the object and after a time a pearl would be produced. It was not until 1890 that the Japanese began to do this on a large commercial scale. Today cultured pearls are common place.

Originally, in the past, to put the foreign substance into the shell was like performing a painful surgical operation, and it was not always successful. Indeed, the head of a great Japanese pearl culture industry once estimated that forty-five percent of the molluscs died. He even went as far as to erect a monument to the molluscs that had given their lives to build up a great industry for Japan.

He had scientists, working as carefully and skillfully as a great surgeon, and using anesthetics, who could actually tell that the pearl was not natural, and an unassted product of th epearl oyster.