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  • FREQUENTLY ASKED QUESTIONS ABOUT AUSTRALIAN SOUTH SEA PEARLS

    FREQUENTLY ASKED QUESTIONS ABOUT AUSTRALIAN SOUTH SEA PEARLS | The South Sea Pearl
    Q:
    What is a pearl made of?
    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. Layers of nacre build up to make a pearl.




    Q:
    How much time does it take to complete a strand?
    Strands made of Australian South Sea Pearls up to 15mm are often put together from one harvest. Exceptional strands often take three or more harvests. Some have taken much longer. But the answer is not so simple, because we have been stocking our large pearls for at least the past 10 years to enable us to assemble strands in these sizes. So it is possible that a strand has one pearl from harvest 2004 and another from harvest 1994.

    Q:
    What area in kilometres are the pearl farms spread across?
    The farms are dotted along more than 2,500 kilometres of coastline – from the Cobourg Peninsula to Exmouth on the north-west Australian coast. An equivalent distance to from London to Moscow! This coastline is in the heart of North Australia’s cyclone belt which annually faces the world’s fiercest tropical storms – a management task in itself to ensure the ongoing viability of the pearl project and the safety of the workers who tend the oysters daily throughout the year.

    Q:
    What year was Australia’s first farm (Kuri Bay) established?
    Kuri Bay’s history extends to the post-war resurgence of the pearl coast. This remote settlement was founded in 1956, as Australia’s (and, indeed, the world’s) first South Sea pearl farm.
 Kuri Bay was named for Tokuichi Kuribayashi of Nippo Pearl, the company that provided the technical expertise for this early farming joint venture.

    Q:
    Which order of importance are the 5 virtues of pearl ranked in when pricing a pearl?
    Lustre, Complexion, Shape, Size, Colour.

    Q:
    What size (age) is an oyster before it can be seeded?
    Approximately 3-4 years before the first operation.

    Q:
    What months are seeding and harvest done each year?
    Annually from May to September.

    Q:
    What is the millimetre size of a nucleus?
    It varies depending on the size and health of the oyster. More important is the nacre thickness. Akoya pearls have a nacre thickness of only around 0.1mm, whereas on a 13mm Australian South Sea pearl the average is 2-4mm.

    Q:
    What is a nucleus made of?
    The best nucleus is made from 100 per cent hand-selected Mississippi clam shell. Ongoing research provides unequivocal evidence that the Mississippi clam shell produces the best results, sharing the specific gravity and almost identical composition to the nacre of the Australian South Sea pearl, ensuring an end product of the highest quality and durability. It is common for Chinese Freshwater pearls to use a lower grade material, such as plastic, for the nucleus.

    Q:
    How many people are employed in the Australian pearling industry?
    Approximately 800 employees currently work across the pearl production divisions of the business.

    Q:
    How often are the oysters cleaned?
    Each oyster is cleaned by hand at least once a month – at slightly shorter periods during the Dry season and longer periods during the Wet season.

    Q:
    How many times can an oyster be seeded?
    Generally an oyster is seeded only the one time, occasionally twice and rarely a third time.

    Q:
    How long does it take for a pearl to grow?
    Australian South Sea pearls grow over a 2-3 year period. Other South Sea pearls grow over 1-2 years, and Akoya pearls take only 6 months (on average) to grow.

    Q:
    How big can an oyster grow?
    Bigger than a dinner plate; approximately 50 years of age.

    Q:
    How durable are Australian South Sea pearls?
    The durability of all pearls cannot be described as if all pearls are homogenous; e.g. untreated pearls are much more durable than treated pearls (treatments are processes such as dyeing, bleaching and enhancing lustre by chemical treatment).


    Akoya pearls are generally the most fragile and least durable of all cultured pearls due to their thin coatings of nacre. Akoya pearls are also almost always treated in some way. As a point of reference, an Akoya is deemed to be good quality if its nacre is 0.15mm thick. Good quality Australian South Sea pearls have on average at least 2mm of nacre. The natural pearl nacre of Australian South Sea pearls will respond well to body oils, etc. Being made primarily of calcium carbonate, it is softer than diamonds and will react adversely to acids which destroy calcium carbonate – as would our teeth.

    Q:
    Why are Australian South Sea cultured pearls so rare?
    The world’s jewellery market is dominated by gold, silver, and diamonds, with pearls representing only 2% in value of total jewellery sales. Cultured Australian South Sea pearls account for just 1% in volume of the global production of all cultured pearls, yet they account for nearly a third of the value. This obvious preference for quality has increased the demand for high quality pearls worldwide, thus pearls of a certain quality will remain scarce, as increases in production take years in lead times, and quantities cannot be easily or cheaply increased by alternative sources.

    While natural Australian South Sea pearls are rarely found in the wild today, cultured pearls are virtually indistinguishable from their natural ancestors.


    Q:
    What gives pearls their shape?
    Only Nature can decide what shape and colour a pearl will be. While the small nucleus or seed implanted in a pearl oyster is round in shape, due to the thickness of the South Sea oysters’ nacre, the pearls emerge in a wide range of shapes. Symmetry is rare in nature, and therefore round shapes are the most highly valued. See The Five Virtues for an explanation of the variety of Australian South Sea pearl shapes available.

    Q:
    What is a cultured half pearl?
    Also known as 'mabe' or 'cultured blisters', the cultured half-pearl is initiated by attaching a hemispherical nucleus on the inside lip of the shell. As the oyster grows and secretes its pearl nacre, the half-pearl grows into a domed blister which is later removed from the shell and backed with mother-of-pearl.

    Q:
    What is an Australian South Sea keshi pearl?
    'Keshi' is a Japanese term which relates to 'small' pearls. They can be either natural or cultured. They can have a solid nucleus (such as a grain of sand), a soft nucleus (such as a small piece of organic material), or a hollow centre, but never an implanted nucleus. As they are impossible to differentiate by eye, all keshi pearls are classified as cultured, unless they are examined by x-ray and accompanied by a certificate from a reputable gemmological laboratory. They generally range in size from 2–10 millimetres and remain quite rare.

    Q:
    What gives a pearl its colour?
    The colour of South Sea cultured pearls is determined only by nature and can be any of the colours of the mother-of-pearl oyster in which it forms. The finest Australian South Sea pearl oysters can display a magnificent array of all the colours of the rainbow, and as such, Australian South Sea cultured pearls are found in a myriad of colours from golds though to silvers and, of course, white. Pearls may also have many different coloured overtones, which sometimes combine with a translucent lustre to produce the effect known as orient.

    Q:
    What is a South Sea pearl?
    A South Sea pearl is produced by the Pinctada maxima - the largest of the pearl-producing molluscs. They are mainly produced in Australia, primarily with wild oysters, and in Indonesia and the Philippines with hatchery-reared oysters.

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  • What do you know about Keshi Pearls?

    What do you know about Keshi Pearls? | The South Sea Pearl

    Keshi (ケシ), meaning poppy seed in Japanese, was originally used in Japan for very small-sized natural pearls, namely the very rare Akoya natural pearls that were locally collected until the early 20th century. Today, however, the original meaning of the word "keshi" became corrupted and is now a trade name for the nacreous non-bead saltwater cultured pearls that form, by accident or intentionally, inside pearl producing molluscs as a by-product of the classic seeding or grafting process. The first reported cultured keshi pearls in the early-20th century were associated to the then emerging Akoya cultured pearl farming in Japan and now "keshis" are are also found elsewhere and in other nacreous pearl producing molluscs (e.g. South Sea, Tahitian). Distinguishing non-bead cultured from natural pearls is very complex, requiring lab experience and modern tools - real-time X-ray microradiography (RTX) and X-ray computerised tomography (µ-CT), and often results in different interpretations. In the image, the Rockpool Styarfish Cuf by Paspaley featuring South Sea keshi cultured pearls gathered over four annual harvests, showing the exceptional character of these rare nacreous biogenic gems that are discovered in very small quantities each year .

    Source: Rui Galopin de Carvalho. (Portugal Gems Academy)

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  • The pearl culture industry in Japan is in crisis after millions of oysters inexplicably died.

    The pearl culture industry in Japan is in crisis after millions of oysters inexplicably died. | The South Sea Pearl

    The pearl culture industry is in crisis after millions of oysters inexplicably died.


    The loss, estimated at 306 million yen ($2.8 million) to date in Ehime Prefecture alone, has not only dealt a savage blow to farms in top-producing prefectures but raised fears that aging farmers may quit the business altogether due to concerns of an extended shortage.


    "I'm worried that some may close their business," said Takao Suzuki, a senior official at the Tategami Akoya Pearl Aquaculture Corp. in Shima, Mie Prefecture.


    Ehime and Mie prefectures account for about 60 percent of the nation’s cultured pearl harvest.


    Officials in Mie cited an increase in seawater temperature early this year as a possible factor behind the oyster blight, but are unable to pinpoint the exact cause.


    In Ehime, researchers are planning an in-depth study into the matter, with no deadline set for completion.


    70 PERCENT WIPED OUT


    In Mie Prefecture, the nation's third-largest pearl producer, Akoyagai oyster deaths were first noticed in June in Shima's Ago Bay and surrounding area.


    The oysters died after the inner layer of their shells shrank. Such deaths have occurred in the past, officials with the prefecture's fisheries research institute said, but this was the first time that they have been observed in summer.


    The institute received a flurry of similar reports the following month, which prompted prefectural authorities to interview 122 cultured pearl farmers, nearly half of the prefecture's farmers, in August in an effort to grasp the extent of the damage.


    It emerged that 1.67 million spat born this spring, or 70 percent of the young shellfish, had perished.


    It takes about 18 months for a shellfish to reach what is known as the "mother stage" that allows a pearl-forming nucleus to be inserted to cultivate pearls.


    As part of efforts to prop up the industry, the Mie Fishery Promotion Foundation will begin artificially incubating larvae of pearl oysters as early as the beginning of next year so farmers can restock.


    This means farmers will have to wait until 2021 for the shellfish to be capable of generating pearls. In the meantime, they almost certainly will face a shortfall.


    In addition to the mass spat fatalities, a prefectural government study showed that more than 20 percent of mother shellfish inserted with a nucleus and shellfish born last year died.


    FEAR OF EXODUS


    Suzuki said bleak prospects owing to the die-off could prompt many older farmers to leave the industry.


    "The industry is graying fast," he said. "Farmers may lose their motivation to continue with pearl cultivation if shellfish are not available.”


    Ehime Prefecture, the nation’s top pearl producer, finds itself in a similar predicament, with a massive death toll among young and mother shellfish.


    Pearl farmers in Ainan and Uwajima facing the Uwa Sea discovered in mid-July that a large number of juvenile pearl oysters had died.


    “Seventy to eighty percent of young shellfish I raised with great care are now gone,” said a 67-year-old pearl farmer in Uwajima. “I can't help but worry about my future.”


    Another farmer lamented that his young oysters have become "nearly extinct."


    According to a report released on Oct. 18 by the Fishery Cooperative Federation Ehime, 22.3 million juvenile shellfish, or 67 percent of those born this past spring, are believed to have died as of the end of September. In addition, 4.69 million mother shellfish died before insertion of a nucleus, accounting for more than 20 percent of such stocks.


    The damage to spat stocks was estimated at around 67 million yen, and about 239 million yen for mother shellfish.


    As for possible factors for the mass fatalities, a Mie prefectural government study in September cited higher than usual seawater temperatures during the first months of this year, as well as a paucity of plankton that shellfish feed on.


    However, prefectural officials have yet to reach a definitive conclusion.


    Such factors “may have contributed to the widespread deaths, but they are not the true cause,” a prefectural official said.


    Scientists at the National Research Institute of Aquaculture in Minami-Ise, Mie Prefecture, suspected a possible infection of a transmitted disease among the shellfish, but none has been confirmed.


    Ehime Prefecture formed a task force comprising prefectural officials, fisheries representatives, university researchers and others to respond to the crisis.


    Four scientists are tasked to work together to identify the cause of the deaths, with no set deadline.

    Source: The Ashahi Shimbum 

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  • Mabe Pearl or Cultured Blister?

    Mabe Pearl or Cultured Blister? | The South Sea Pearl

    Mabe Pearl or Cultured Blister? A pearl is a concretion of biomineralized aragonite and/or calcite with minor organic matter (conchiolin) produced inside a pearl sac in the interior of marine or freshwater molluscs. A cultured pearl is basically the same, but formed with human intervention inside a cultured pearl sac. The so-called "mabe pearls" are not however, technically, pearls in the sense that they do not grow inside a pearl sac. In fact, these are protuberances in the shell’s nacreous interior that form as a consequence of a culturing process, being defined as cultured blisters, that are worked, cut from the shell (soft nuclei removed), the interior filled with a hardened substance and finished with a mother-of-pearl cap glued to the base, making it an assembled product, hence an assembled cultured blister. The name “mabe” comes from the Japanese vernacular for Pteria penguin (mabe-gai), a pearl oyster that was extensively used to produce these cultured blisters. In the images, a strand of bead cultured pearls, an assortment of cultured blisters, a pendant and one still on the shell, grown in the rainbow-lipped pearl oyster or “ostra nácar” (Pteria sterna) in Guayamas, Gulf of California, Mexico © Perlas del Mar de Cortez

    Source: Rui Galopim de Carvalho / Portugal Gemas Academy

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