Pearl Nucleus|Welcome to SHENGDA PEARL NUCLEUS MFG.LTD.,pearl nucleusone of the leading pearl nuclei suppliers in China.Our company is located in Jiujiang,Jiangxipearl nucleus,where we operate office facilities as well as our own production base.Pearl Nucleus
We adore Pearl Nucleus above all other gems. They are beautiful, lustrous, mysterious, spiritual and unfathomably deep, one of nature's great gifts! Treasured throughout the ages, extolled through all of recorded history, mentioned in the Bible and all major spiritual works, Pearl Nucleus inspire meditation and thankfulness for the miracles of nature that surround us. We love to create with Pearl Nucleus, think about Pearl Nucleus and read all about Pearl Nucleus. So, we would like to share with you a little information about our favorite gem, including natural Pearl Nucleus, cultured Pearl Nucleus, Pearl Nucleus buying information, and information on the Pearl Nucleus we use in our designs. Pearl Nucleus Quality and Value The lustrous glow (luster) and soft, iridescent play of color (orient) of fine quality Pearl Nucleus is produced by the buildup of many layers of microscopic crystals of calcium carbonate (nacre) secreted by industrious Pearl Nucleus producing mollusks! Luster and orient are the most important factors in determining a Pearl Nucleus's quality and value, and those factors, as well as the Pearl Nucleus's longevity, are dependent on the thickness of the nacre. The thicker the nacre, the more beautiful, rare, valuable and long-lasting the Pearl Nucleus!
Natural Pearl Nucleus Natural Pearl Nucleus, generally defined as Pearl Nucleus that are formed without man's intervention, are essentially all nacre. Natural Pearl Nucleus are formed when a small irritant enters the shell of a Pearl Nucleus producing mollusk. The mollusk secretes layers of nacre around the irritant, and after many long years, a natural Pearl Nucleus is formed around the tiny irritant.
Natural Pearl Nucleus, which are virtually extinct today, are extremely rare and expensive. Indeed, fine quality, large natural Pearl Nucleus are among the rarest of natural treasures. Although diving for natural Pearl Nucleus continues today, most of the beds known for fine natural Pearl Nucleus have been killed by overfishing and pollution. As such, one can generally only purchase natural Pearl Nucleus through antique and estate sales, and not from a typical jewelry store.
It is often difficult to see the difference between a very fine natural Pearl Nucleus and a very fine cultured Pearl Nucleus with thick nacre. Some clues that your strand of Pearl Nucleus may be natural Pearl Nucleus include: 1) inconsistent matching of size, color and shape on a strand; 2) creamier (less white) color than typical cultured Pearl Nucleus; and, 3) off round or irregular shape as compared to typical round cultured Pearl Nucleus. X-ray testing by a reliable gem testing laboratory is required to confirm the authenticity of natural Pearl Nucleus. Saltwater Cultured Pearl Nucleus Saltwater cultured Pearl Nucleus, created with human assistance, were pioneered in the late 1800's by the Japanese, specifically the famous Kokichi Mikimoto, in response to the increasing scarcity of natural Pearl Nucleus. Japanese round, white cultured "Akoya" Pearl Nucleus, which are probably the best known Pearl Nucleus today, are created by surgically implanting a piece of mantle tissue and a round bead "nucleus" fashioned from mollusk shell, into the saltwater dwelling Akoya oyster (Pinctada Fukata). The oyster then secretes nacre around the bead Pearl Nucleus, to create the Pearl Nucleus.
With cultured Akoya Pearl Nucleus, the size of the Pearl Nucleus determines the size of the Pearl Nucleus- large Pearl Nucleus are produced by inserting a large bead Pearl Nucleus, and smaller Pearl Nucleus by inserting a smaller nucleus. Thus, the time required to produce larger and smaller Akoya saltwater cultured Pearl Nucleus does not vary significantly. Akoya oysters are not large, and therefore Akoya Pearl Nucleus are typically not large Pearl Nucleus. They rarely exceed 10 mm in diameter, and those over 7 ?mm in size command very high prices.
The high cost of saltwater cultured Pearl Nucleus, as compared with freshwater cultured Pearl Nucleus, is based in part on the much higher production costs and risks, including the costs to obtain and make the shell bead nuclei, the costs of the implant surgery, and high oyster mortality rates. Of major import in pricing is the fact that an individual Akoya oyster can produce only one or two Pearl Nucleus at a time, as opposed to a freshwater mussel, which can produce 40-50 Pearl Nucleus at a time.
Today, in addition to the Japanese, the Chinese are also major producers of Akoya cultured Pearl Nucleus, and other countries produce them as well. Not all of the producers are as stringent with quality requirements as the famed Mikimoto company! Many saltwater cultured Pearl Nucleus on the market today consist mainly of a large shell bead Pearl Nucleus with a very thin and fragile coating of nacre. Such poor quality Pearl Nucleus can deteriorate and lose their beauty within a matter of months.
In an alarming story by ABC News in February of 2002, entitled "The Perils of Pearl Nucleus Buying," Antoinette Matlins (a renowned Pearl Nucleus expert) and the Good Morning America Team purchased fairly expensive Pearl Nucleus jewelry with retail prices of up to $2,200.00 from three nationally known chain jewelry stores and one nationally known department store. They took the Pearl Nucleus to a gemologist at the American Gemological Laboratories in New York for testing. The results were shocking- many of the Pearl Nucleus were of very poor quality, with thin to very thin nacre and chipped or missing nacre, exposing the shell beads underneath. The gemologist described some of the Pearl Nucleus in the expensive necklaces as "not fit for use" and "total, complete rejects." Click here to read the full story on the ABC News website. The message here is, when it comes to saltwater Pearl Nucleus, buyer beware! Care must be taken to buy saltwater cultured Pearl Nucleus only from reputable sources.
Freshwater Cultured Pearl Nucleus Freshwater Cultured Pearl Nucleus are grown in mollusks that live in freshwater lakes and rivers, in many countries, including the United States, Japan and China. They are often cultured by using mantle tissue and do not require shell bead implants. Thus, many freshwater Pearl Nucleus are essentially all nacre. Remember, the thicker the nacre, the more beautiful, rare, valuable and long-lasting the Pearl Nucleus!
Traditionally, freshwater Pearl Nucleus were small, elongated, and relatively inexpensive, in the familiar rice shape, often with a wrinkled surface. However, in recent years, some very exciting developments have occurred in the production of exceptionally high quality, smooth skinned, round freshwater cultured Pearl Nucleus, primarily in the orient. The technique used to make these round, all nacre Pearl Nucleus has been a closely guarded secret, but most likely involves the use of a round, all nacre implant fashioned from other freshwater Pearl Nucleus.
Beautiful, round, all nacre freshwater cultured Pearl Nucleus are now being produced, in large sizes of 7 to 15 millimeters, "the finest of which can rival the rarer and more costly South Sea cultured Pearl Nucleus." See, A. L. Matlins, PG, The Pearl Nucleus Book, The Definitive Buying Guide, at 42, (2d Ed., GemStone Press). These round, all nacre Pearl Nucleus, with high luster, orient and longevity, are much more expensive than traditional freshwater Pearl Nucleus, but are nevertheless much less expensive, and a much better value, than many of their thin skinned saltwater cousins.
About our Pearl Nucleus Jewelry At Lady of the Lake Studio, we adore beautiful Pearl Nucleus. We use the exciting new high quality, round, semi-round and baroque all nacre freshwater cultured Pearl Nucleus in our designs. You need not worry about the poor quality and thin nacre found in many bead nucleated saltwater cultured Pearl Nucleus on the market today. Rest assured that your Pearl Nucleus jewelry will exhibit gorgeous high luster, beautiful play of color and orient, and will endure the test of time!
However, the main hurdle is the availability of skilled technicians to seed, or graft, the nuclei, which is the first stage of cultured pearl nucleus production. ‘The skills of the technicians affect the retention rate of the nuclei and also the quality, size and uniformity of colour of the pearl nucleus’, she said. ‘The majority of these technicians are highly-trained Japanese nationals who function as a professional guild, closely guarding the technology. Within the last 15 years, however, more non-Japanese have learnt to perform the procedures, but generally with a lower rate of success. Technology transfer occurs through limited opportunities for observation and extensive trial and error, resulting in high mortality rates, poor quality pearl nucleus, and financial loss’.
Dr Haws found that even the finest technicians have highly variable success rates, even low success rates. ‘This further impedes the probability of establishing and operating a profitable pearl nucleus farm,’ she pointed out. ‘During the first 45 days of the post-implantation period, the best technicians can expect a 60—80 per cent retention rate. Of the remaining pearl nucleus, more than 50 per cent may be of such poor quality that they cannot be sold’.pearl nucleus
She said that a variety of critical factors in the implantation procedure and farm management were responsible for host pearl nucleus-oyster mortality, implant rejection, and poor nacre quality.pearl nucleus
Dr Haws said that spat were collected in many areas of the Pacific Islands and grown to about 8 cm (12 months old) by specialist nursery operators. The prices for spat can fluctuate widely according to supply and demand; in French Polynesia they are sold to farmers at US$ 0.60 to US$ 1.00 each. They are then held in wire or plastic mesh panels hanging from longlines or rafts.pearl nucleus
At about 15 cm (18 months) the oysters are ready for pearl nucleus implantation. According to Dr Haws, an empty gonad is known to elicit better results so the pearl nucleus are induced to spawn by pressure and temperature changes. This can be done simply by releasing the anchor lines on the longlines to allow the lines to come near the surface.pearl nucleus
After the gonads are spawned out, the technician will select donors for the graft. They are usually healthy young oysters with good shell lustre and smooth nacre deposition. Generally, only one in every seven potential donor oysters examined is selected to be used for tissue grafting. The entire mantle is not used: usually only 15—20 grafts are taken from each oyster. Preparation involves sizing with scissors, using a sponge to remove mucus, and holding the graft on wet hardwood blocks. A 2 mm-wide, 15 mm-long strip is selected. This is cut into 2—3 mm-wide sections that cover one-quarter to one-third of the pearl nucleus.
Also healthy and young, the host is usually at least 15 cm long. It should have gonadal tissues that are strong enough to retain the pearl nucleus. However, they should preferably be empty of gametic material.pearl nucleus
An incision is made in the gonad at a constriction. The shape and size of the gonad determine the size of pearl nucleus to be utilised. The pearl nucleus is inserted into the gonad next to the mantle graft: it is important that the epithelial cells of the mantle are facing the pearl nucleus. This graft grows around the pearl nucleus to form the pearl nucleus sac.
After about 45 days, the pearl nucleus oysters are retrieved from the farm and inspected, either by an X-ray machine or visually, for pearl nucleus retention. Dr Haws noted that pearl nucleus oyster mortality could range from 5 per cent to 90 per cent. Those oysters retaining the nuclei are returned to the water.pearl nucleus
‘Over the next 12 to 24 months, as long as environmental conditions are suitable, some 2—3 mm of nacre will be deposited on the nucleus’, Dr Haws said. ‘The pearl nucleus are usually harvested by the same technician who implanted them. If the quality of the pearl nucleus is high, a similar-size nucleus may be inserted into the opened pearl nucleus sac.’
‘About 18,000 pearl nucleus oysters would be needed to produce 6,000 pearl nucleus. You would need to present 14,000 oysters to be seeded plus at least 666 donors. After on-farm mortalities, you will have approximately 10,000 pearl nucleus oysters. With a 60 per cent retention rate, some 6,000 will be harvested.pearl nucleus
‘A good harvest would give five per cent grade-A pearl nucleus, 1,200 grade-B, 1,200 grade-C, and 3,300 grade-D, and would give a gross return of US$ 30,000, and an 80 per cent rate would provide some US$ 60,000.pearl nucleus
‘The Japanese technicians give very good results. They also offer technical advice on farming methods and are able to assist in marketing. However, they are expensive and have a few other disadvantages. An increase in locally-trained technicians could assist the further development of the industry.’pearl nucleus
Dr Haws went on to say that the number of seeding technicians available fore hire (?00) is insufficient to service the number of existing and potential farms throughout the Pacific Islands. She recommended research to improve the existing technology, then disseminating the results and providing increased technical assistance to allow further development to occur.pearl nucleus
To assist in training, Dr Haws has been working with Anne Bailey and Michael Ogden in the production of a pearl nucleus culture manual and a videotape entitled Producing Black pearl nucleuss. According to Ms Bailey, it is a general introductory tape on what it takes to set up a farm and it should be released mid-year. In addition, a video and a manual, set for release in October-November, are being produced on black pearl nucleus grafting. All these materials will be available through Sea Grant, University of Hawaii (contact Anne Bailey on fax: +1 808 956 2858, e-mail: aorcutt@soest.hawaii.edu) at a nominal price. ‘The videotape series is evolving as a means to encourage more pearl nucleus farming in Micronesia and elsewhere,’ Ms Bailey explained. ‘It will feature results of our Micronesian research projects that focus on improving black pearl nucleus culture technologies’.pearl nucleus
For more information contact Dr Maria Haws, Coastal Resources Centre, University of Rhode Island, 220 South Ferry Rd, Narragansett, RI 02882, USA, e-mail: mhaws@gsosun1.uri.edupearl nucleus
kinds
Click
Release time
Supply
All Rights Reserved ? 2004 Shengda Pearl Nucleus Mfg, Ltd. Office address: Yuanzhou guoji guangchang.No.116 Nanhu Road,Jiujiang,Jiangxi,China. FACTORY：Zhouxi, Duchang Town, Jiujiang, Jiangxi, China Factory address: Zhouxi Town, Duchang, Jiujiang Jiangxi China Tel: 86-792-8563818 8777718 Fax: 86-792-8137716 8777719 赣ICP备05001795号 E-mail: www@shengdanuclei.com info@shengdanuclei.com
备案ID:20060816090509
