Some believed pearls to be the tears of the gods. Others thought them dewdrops filled with moonlight that fell into the ocean and were swallowed by oysters.
A pearl is a natural gem created by a living organism. When a foreign object is introduced into a mussel or oyster the animal coats the irritant with a substance called nacre, the same material with which it builds it's shell. Over time, the layers of nacre build up to form the pearl. The longer the irritant remains in the mollusc, the more layers of nacre and (usually), the better the pearl.
Seawater Pearls have a round shell bead (usually from an American freshwater mussel) inserted as the irritant. This is refered to as 'nucleating'.
Freshwater Pearls have a piece of mantle tissue (nacre producing tissue from another mussel) introduced as the irritant. Freshwater pearls are non-nucleated.
Which is better ?
No matter where they come from or how they are cultivated all pearls are made of the same substance - calcium carbonate.
Strands of pearls are judged and graded by their individual qualities - size, shape, lustre, matching, blemishes or lack of them. There's no 'better' or 'worse' - it simply depends on the pearl.
Most wild, natural pearl producing oyster beds have vanished due to over-fishing and pollution. Today, the world's most beautiful pearls are cultured.
Cultured pearls share the same properties as natural pearls. The only difference is that a technician opens the shell and inserts the irritant. Nature then takes over.
Seawater oysters are suspended in the water from rafts above and are subject to tides, typhoons, parasites, predators and even barnacles.
Freshwater mussels are cultured in the same manner but in inland lakes and rivers.
Harvesting pearls is a time consuming process. Of the millions of oysters and mussels 'seeded' each year, only a proportion (maybe just 50%) will survive to bear pearls. Of these, many will not produce pearls of a marketable quality.
Myth
Many people think of wild oysters ingesting a grain of sand as the foreign body which stimulates nacre production.
Living in the sea, oysters are constantly ingesting and expelling sand and irritants.
Only when something becomes lodged - like a piece of shell, bone, coral or parasite does the oyster start nacre production.
Shapes & Colours
Pearls come in a bewildering array of shapes and colours.
Shapes include round, drop, oval, button, semi-round & baroque. Round and drop pearls are usually the most expensive.
Some breeds of mollusc tend to produce particular pearl colours. Black and Gold South Sea pearls are highly prized.
Very Interesting....
tao abar picchi ekta..
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