Japanese-Australian Triumph

 January 2 1960

The Biggest Pearls Ever

Kuri Bay, a remote inlet on the coast of North 'Western Australia by Japanese in the service of Pearls Proprietary Ltd.,. an Australian company jointly financed by American,

Australian and Japanese investors, was sold in New York recently for $100,000. To the most expert eye the gems : are indistinguishable from natural pearls: that they are artificially produced can be detected only by X-rays or by special microscope. Jewellers overseas say this Is perfection never before attained in pearl culture. The texture of a cultured pearl Is. usually coarser, its lustre less exquisite than that of a natural pearl But no expert has yet identified one of these West Australian pearls without scientific aids.

Pearls of a diameter less than 11 millimetres — about three quarters the diameter of a dime — are not produced at Kuri Bay, because Pearls Proprietary Ltd. has agreed with its Japanese partner, the Nippon Pearl Company, not to produce smaller gems. Pearl culture has been confined In the past to Japan, where it is a lucrative Industry. Only the Japanese know me secret of inducing; oysters to excrete pearls. But the oyster they use Is of medium size and it produces pearls to a maximum diameter of 11 millimetres.

So when the Nippon Pearl Company suggested to Brown and Dureau, a Melbourne merchandising company, that it might be worth while experimenting in the culture of pearls from the giant silver lipped pearl oysters fished off the North-West coast of Australia, it stipulated that Australian production, it shown to be practicable, should be confined to pearls of larger diameter. The bargain proved an even more vital protection for Japanese pearlers than the Japanese realized when they imposed it Not only have the

Australian oysters produced larger pearls, they have grown them nearly three times as fast as the Japanese. In Japan it takes four or five years to produce a cultured pearl. At Kuri Bay, pearls are harvested after 22 months.

 Of the 100,000 oysters under observation at Kuri Bay, however, only number of oysters would be much higher The Japanese breed oysters one In three produces a pearl and many of these are so misshapen or discolored as to be valueless. In Japan the yield of marketable pearls from the same for pearl culture. The oysters used at Kuri Bay will not breed in captivity. Every oyster laid down there must be brought in from luggers operating off the West Australian coast and those chosen for culture must be of a particular age and size  Since nobody can predict a lugger's catch these  requirements add considerably to the costs of the Industry. The pearls are laid down in waters where the tides rise and fall 30 feet Rafts to support thousands of oyster baskets are built and moored. As oysters are brought in by the supply ship which gathers them from the luggers they are carefully graded, then handed over to an expert who persuade them to open for seeding. Spheres of machine  turned shell from a mussel imported from the delta of the Mississippi are inserted In small incisions In the mantles of the oysters and a piece of tissue from. Another part of the mantle is grafted over the seed. If the wound heals the oyster proceeds to cover the foreign body with layer upon layer of nacre, the lustrous substance that composes every pearl, natural or cultured. The more layers of nacre, the larger the pearl and the finer its texture.

Some oysters do not survive the operation. Others eject the seed. Others die before the pearl Is completed. So all baskets containing seeded oysters must be checked periodically for symptoms of disease. Dead or dying oysters must be replaced and others opened before the pearls they have produced begin to discolor. All parasites must be removed from the shells because clean oysters produce the best pearls.

Kuri Bay is is tropical, barren country but the Japanese experts have comfortable living and working quarters. They sign on for two years and earn good money by Japanese standards. This Is not the first time-an attempt has been made to produce cultured pearls on the North Western Australian coast Thirty years ago a similar venture was launched; but before it could reap a harvest the pearlers at Broome, headquarters of the industry In W.A., demanded that the beds be uprooted lest cultured pearls drive natural pearls off the market The Government of that day yielded to the demands but since then natural pearling has had some ups and downs and Australian horizons have widened.