Sunday, February 3, 2002		Article

In pursuit of precious pearls
Veryam Kaur Trewn & Trilochan Singh Trewn

FOR thousands of years, a pearl has been an object of decoration for both men and women, a precious marine gem found by human beings from oysters from seabed and riverbeds. A natural pearl is a concretion formed by a mollusc consisting of the same material (called nacre or mother of pearls) as the mollusc’s shell. A pearl is characterised by its translucence and lustre as well as its delicate play of surface colour. Amongst pearl-loving tourists, majorca pearls and mikimoto pearls sold at airports and elite shops, are quite popular.

We were aware that Japan was the home or variety of pearls and so were curious and restless when our ship anchored in Chiba Bay close to Tokyo on Christmas Eve. The sparkling shore lights in Chiba Bay were simply bewitching. Our determined quest for the right place where we could select and understand the right variety of pearls at an economical rate, took us to the famous Ginza Departmental complex. It is located right opposite the Tokyo Central Railway Station. The seventh floor of the majestic building had only all pearl counters attended by sleek white roped Japanese damsels. One of them knelt and handed over to us a brightly-illustrated catalogue. We enquired about the three artistically stringed pearl beads displayed.

In large blue velveted counters. Prices quoted were 1000 yens 10,000 yens, 100000 yens, respectively. We knew hardly anything about the chemistry of these pearls and the reasons of the price differential because all three stringed beads looked alike. We were informed that the first one was an artificial or imitation the second was a cultured pearl string and the third one consisted of pure, natural pearls.

The manager invited us to an organised visit to a pearl farming vessel anchored 50 km south of Tokyo Bay during which the entire process and production of natural and cultivated pearls were to be demonstrated and explained through an English-speaking guide on the vessel. The guide explained to us how real natural pearl farming industry was modernised in 1960. Prior to this, pearl farming was done by skin divers with bare loin-cloths and the diver used to go down to depths of 60 to 80 ft with clip punches on nose to prevent water entering the nostrils. The oyster shells were pulled out from low lying rocks with slip leather sheath on fingers. He hurriedly collected oysters and filled the bag around his neck during 90 seconds he could stay below. The shells on board were opened in search of pearls. The discarded oysters were tossed back into sea.

This procedure had been mechanised for modern pearl farming and regulated by the control vessel. A driver now uses diving suit well-equipped with under-sea vision glasses and breathinglines. Thus, he can now remain for longer periods below and have larger profitable catches. The guide elaborated, that a natural pearl is of the oyster’s own making. A fine grain of sand or a tiny creature floats between two halves of the shell. The oyster cannot drive it out and covers it with successful layers of the same substance with which it smoothlines its rough shell. This substance is called nacre or mother of pearls, and in such situations a natural pearl is formed. The chief compound of the nacre, which constitutes the pearl is argonite (CaCo2) The colour of a natural pearl varies with the mollusc and its environment. It ranges from black and white to cream, grey, blue, yellow, lavender and green. We were shown pearls weighing from ½ carat (seed pearls) to largest ones weighing 445 carats, known as baroque pearls. The widespread use of cultured pearls has reduced the production of natural pearls. The Persian Gulf produces very fine pearls called Mohar Pearls, round at depths of 48 to 120 feet. Majorca, gulf of Mannar, Gulf of Mexico and Japan also produce good pearls. Indonesia produces dark-coloured-pearls with a metallic sheen.

Natural fresh water-pearls are also found in rivers but these are generally small and inferior. These are white, opaque and less shining in appearance. Fresh water pearls of the Mississippi river are famous.

Cultured pearls are produced by use of nacre found in natural pearls. A tiny nacre bead is inserted in the body of another oyster. The cultured oysters with other similarly prepared oysters are placed in thin meshwire baskets. We were shown hundreds of such baskets suspended from a raft close by and lowered into the sea. These were to be left suspended for three to four years. During this period, the treated oysters thrive and produce shining pearls. Their value depends upon their size and shape. Such sea water pearls were known as orient pearls.

In Japan, the first organised cultured pearl farming industry was started in 1890 by Mikimoto Kokichi. The master of vessel stated that life of a pearl depended upon the thickness of nacre and its contact with acids of human body which deteriorate the pearls’ nacre layer on it. We also noticed that, considering the high value of the pearls, there was a tight security check on the ship’s jetty. There were sophisticated X-ray facilities installed on board to confirm whether the core of a pearl was natural or cultured.

In case of artificial or intimation pearls, no oysters are utilised. These are glass beads with surfaced covered with a substance made out of fish scales. Often, a hollow glass beads is lined with fish scale compound and is then filled with white wax which is visible through the hole.