Cultured Pearls

CULTURED PEARLS
PRECIOUS BEAUTY FROM THE SEA OF SABAH IN MALAYSIA

Introduction

Long before man began interfering with nature, the sea yielded natural, varied and highly prized gems -- pearls. Pearls have been used for jewellery as well as medicinal purposes by the early Greeks, Asians and Pacific Islanders. For nearly 5,
0 years we have been enjoying these gems but it is really only in the Iast century that pearls have become a cultivated commodity. Though many countries are now cultivating pearls. the Japanese are acknowledged as the undispuled experts in this delicate field of work.

In IvIalaysia, a local joint venture with Japanese owned pearl culture farm namecl Syarikat Kaya Pearls Sendirian Berhad has been established since 1963 to cultivate these gems in Bohey Dulang Island some 18 km from Semporna town in the state of Sabah (Fig. 1 & 2). The project site covers an area of about 11.5 hectares.

Species

Currently, this company is rearing the silverlip oysters Pinctada maxima for culturing pearls (Fig. 3). Comparatively, this species can produce better quality pearls.

Inserting the nucleus

Before the nucleus can be inserted, the mother oyster is artificially induced to spav
n and thus expend its excess energy. Then a section of the mantle lobe (called a piece) from another mollusk is cut and prepared, the oyster is secured on a shell stand, an incision is made in the soft tissue with a sharp surgical scalpel, the piece is inserted, and the nucleus is placed right beside it

The implantedp
ece grows to form apeorl-sac around tbe nucleus, enveloping it with a thin layer of a secreted nacreous material. It is from the surface cells of this pearl-sac that nacreous substance is excreted, forming three to four layers a day and completing the pearl-making process in a year or two.

Method Of Culture

Syarikat Kaya Perals Sendirian Berhad is using the floating rafts and cages method for rearing the pearl oysters in the sea near Bohey Dulang Island in Semporna.

Types Of Cultured Pearls

The company is currently producing two types of cultured pearls, ie. round pearls and half-round pearls (Fig. 5). It takes about two years to culture round pearls and about ten to twelve months for half-round pearls. For culturing half-round pearls of this duration, the cultured pearls can normally attain a diameter of 15 - 20 mm.

Marketing Of Cultured Pearls

All the cultured pearls are exported to Japan in the unprocessed form. These cultured pearls will be processed in Japan and later either marketed in Japan local markets or exported to other countries.

Difference Between Cultured And Natural Pearls

Though there was much speculation as to the authenticity of pearl cutlrue in the early 1900s, cultured pearls are, indeed, every bit as genuine as natural pearls. The only difference is in the nature of the nucleus around which the pearly substance forms. In natural pearls, sand particles, parasite eggs and other foreign objects form the centre of the sphere, whereas an artificial nucleus of shell origin (bivalves) is inserted to cultured pearls (Fig. 6). The pearl-forming process is both identical. In other words, once there is a nucleus, natural or man-made, r.acre begins to form layers of the precious bead.

Distinguishing Good Pearls

The important criterion when assessing a pearl is the perfection of its surface. A flawless pearl is unbeatable, but one can overlook a small speck or dimple. Roll the pearl with the tip of the finger to check for flaws; if the ball has more than two, it is not good for a ring. Those with fime surface grin, good lustre and preferably with a banded gleam are Lhe best for rings (Fig.7
. Those that look heavy are sure to have thick layers of nacre and should have lasting quality, while thin-layered balls should be avoided. Pearls with slight blemishes can be used in necklaces but not in rings (Fig.8).

The price of pearls is dictated by size rather than quality. For example, the price of loose pearls augments progressively for each millimeter of diameter. In other words, the prices for a 7 mm pearl and for an 8 mm pearl are vastly different.

Colors Of Pearls

The color of pearls can appear in these colors: pink, cream-pink, cream, silver, gold, green, black, blue, and brown. The experts say pearls should be chosen to match the color of the skin.

The Care Of Pearls

Slight marks on pearls can be erased by polishing with olive oil. Remember, not to wear in bath, kitchen or washing. Pearis may change colour if wearing to carry out these activities because pearls are made of calcium carbonate.