Pearl culture and history and technique's of pearl culturing

PEARL CULTURING 

Pinctada margaritifera (var. cumingii) and P. vulgaris, which grow to a size of 12–15 cm after three years of culture, are the two oyster species that produce pearl. There are pearl oysters all over the Indo-Pacific. For almost 200 years, they have been fished for the mother-of-pearl industry, and occasionally, the sea has been used to gather excellent pearls.

Spit collection studies were conducted at the start of the 20th century to combat the devastation of natural populations, but the procedure wasn't perfected until the late 1950s. The French Fisheries Service performed the initial grafts during a period of renewed interest in pearls in the 1960s, and the first grafted pearls were harvested in 1965. Through private endeavours, this oyster was first farmed for pearl production in the 1970s, and a market for Polynesian black pearls was created.

CULTURE TECHNIQUES

Spat rearing in hatcheries is still not completely under control. A long rope suspends chains for raising pearl oysters. Spat is gathered for culturing in the wild by placing artificial substrates. The oysters are placed on oyster-rearing chains hung from beneath long lines at a depth of 6 to 10 m after reaching a size of 5 to 10 cm after 12 to 24 months of unassisted growth. On each of these 200 m long, 10 m apart oyster-rearing chains, 4,000 to 10,000 oysters are placed.

After 3-12 months, the oysters attain a size of roughly 10 cm and weigh about 120 g, and at this moment they are ready to be grafted. The oysters are once again placed on lengthy lines after grafting and left there until the pearl matures, which typically takes around 18 months. The laws prescribe a maximum density of 2,400 oysters per 200 m oyster-rearing chain. Only 25–30% of these oysters generate pearls that may be sold; the remainder are rejected, die, or produce pearls of inferior quality.

Pieces of one mollusc's mantle are inserted into another's gonad to create the kechi pearl. There won't be a need for a nucleus, and up to 20 pearls may be formed, however the final product will be a tiny, less than 7 mm, odd-shaped pearl. The term "baroque" refers to pearls that are larger than 7 mm that are created when a nucleus is employed. Because they are relatively simple to implant, mabe pearls are widely grown by American pearl companies.A semi-spherical core is put beneath the mantle and progressively covered by nacre to form a half pearl (plastic in the case of the Cross and Peach type and mother-of-pearl in the case of the Latendresse type). By adding nuclei of various forms, the same oyster can create several shapes like rounds, kechis, baroques, and mabes.

History

Natural pearls are harvested from the sea using an expensive, time-consuming method that yields very few pearls. Pearls were therefore incredibly uncommon and expensive. It wasn't until the Japanese figured out how to nucleate mollusks to make cultivated pearls that individuals other than the very affluent could purchase pearls.

The son of a noodle maker, Kokichi Mikimoto, collaborated with his devoted wife Ume to create a method that encouraged oysters to produce pearls on demand. It was this finding that led about the commencement of oyster farming and pearl production. Tokichi Nishikawa, a government biologist, and Tatsuhei Mise, a carpenter, had independently discovered the source of pearl production at the same time.

These discoveries helped cultured pearls develop into a significant and competitive technology, as did Mise's 1907 patent for a grafting needle. They were completely unaware of one another's work until Nishikawa submitted an application for a nucleating patent and learned that Mise had made an identical discovery. Together, they developed the Mise-Nishikawa technique, which is still the cornerstone of modern cultured pearl production. Mikimoto developed a way to culture round pearls after further modifying the Mise-Nishikawa approach. After this patent was issued in 1916, Mikimoto's creations eclipsed those of everyone else. For instance, Mikimoto's work directly contributed to the creation of the Akoya pearl.

Akoya Pearl

In the oceans off the shores of Australia, the Philippines, Indonesia, Myanmar, Japan, and Thailand, South Sea pearls can be found. When European explorers came in the 16th and 17th centuries, the demand for South Sea pearls surged throughout the world, and by the 18th and 19th centuries, the South Sea pearl-producing oysters were on the verge of extinction. Culturing of pearls preserved these oysters, and elevated South Sea pearls to the level of 10% of the global pearl market.

South sea pearl

Originally, it was thought that Tahitian pearls belonged to God Oro, who travelled to earth on rainbows. The pearls were raised in the French Polynesian waters when the French came. By the year 1700, there were so many traders and explorers that the mollusks that produced pearls quickly became extinct, forcing France to take drastic measures and impose strict restrictions on pearl fishing off these islands. Tahitian pearls couldn't again be marketed until the Japanese started the nucleation process.

Tahitian pearl

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