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75-408: The more modern version of the story has a married couple finding ten magical pearls ; the wife swallows all ten pearls in one gulp and gives birth to decuplet sons . Each one of the ten brothers possesses a different supernatural power, though they develop their gifts as the story progresses. At the end, the brothers battle some form of an antagonist and they only win by working together. However, if

150-542: A malacologist would still consider them to be pearls. Valueless pearls of this type are sometimes found in edible mussels , edible oysters , escargot snails, and so on. The GIA and CIBJO now simply use the term 'pearl' (or, where appropriate, the more descriptive term 'non-nacreous pearl') when referring to such items and, under Federal Trade Commission rules, various mollusk pearls may be referred to as 'pearls', without qualification. A few species produce pearls that can be of interest as gemstones. These species include

225-466: A metaphor for something rare, fine, admirable and valuable. The most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as natural pearls. Cultured or farmed pearls from pearl oysters and freshwater mussels make up the majority of those currently sold. Imitation pearls are also widely sold in inexpensive jewelry. Pearls have been harvested and cultivated primarily for use in jewelry , but in

300-473: A South Sea pearl – as described by CIBJO and GIA – is a pearl produced by the Pinctada maxima pearl oyster. South Sea pearls are the color of their host Pinctada maxima oyster – and can be white, silver, pink, gold, cream, and any combination of these basic colors, including overtones of the various colors of the rainbow displayed in the pearl nacre of the oyster shell itself. South Sea pearls are

375-415: A beaded cultured pearl is generally a polished sphere made from freshwater mussel shell. Along with a small piece of mantle tissue from another mollusk (donor shell) to serve as a catalyst for the pearl sac, it is surgically implanted into the gonad (reproductive organ) of a saltwater mollusk. In freshwater perliculture, only the piece of tissue is used in most cases, and is inserted into the fleshy mantle of

450-456: A body color that may be assessed as silver, silver blue, gold, brown-black, green-black, or black. Black cultured pearls from the black pearl oyster – Pinctada margaritifera  – are not South Sea pearls, although they are often mistakenly described as black South Sea pearls. In the absence of an official definition for the pearl from the black all use to, these pearls are usually referred to as "black pearls". The correct definition of

525-414: A natural pearl shows a series of concentric growth rings. A beadless cultured pearl (whether of freshwater or saltwater origin) may show growth rings, but also a complex central cavity, witness of the first precipitation of the young pearl sac. Some imitation pearls (also called shell pearls) are simply made of mother-of-pearl , coral or conch shell, while others are made from glass and are coated with

600-483: A pinkish color. Cultured pearls can often be distinguished from natural pearls through the use of X-rays , which reveals the inner nucleus of the pearl. The cultured pearls on the market today can be divided into two categories. The first category covers the beaded cultured pearls, including Akoya, South Sea, Tahiti, and the large, modern freshwater pearl, the Edison pearl. These pearls are gonad-grown, and usually one pearl

675-475: A solution containing fish scales called essence d'Orient . A well-equipped gem testing laboratory can distinguish natural pearls from cultured pearls by using gemological X-ray equipment to examine the center of a pearl. With X-rays it is possible to see the growth rings of the pearl, where the layers of calcium carbonate are separated by thin layers of conchiolin. The differentiation of natural pearls from non-beaded cultured pearls can be very difficult without

750-450: A species of small pearl oyster, Pinctada fucata martensii , which is no bigger than 6 to 8 cm (2.4 to 3.1 in) in size, hence akoya pearls larger than 10 mm in diameter are extremely rare and highly priced. Today, a hybrid mollusk is used in both Japan and China in the production of akoya pearls. Cultured Pearls were sold in cans for the export market. These were packed in Japan by

825-509: A spherical bead as a nucleus. Most saltwater cultured pearls are grown with beads. Trade names of cultured pearls are Akoya ( 阿古屋 ), white or golden South sea, and black Tahitian . Most beadless cultured pearls are mantle-grown in freshwater shells in China, and are known as freshwater cultured pearls. Cultured pearls can be distinguished from natural pearls by X-ray examination. Nucleated cultured pearls are often 'preformed' as they tend to follow

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900-437: Is calcium carbonate and a fibrous protein called conchiolin . As the nacre builds up in layers of minute aragonite tablets, it fills the growing pearl sac and eventually forms a pearl. Natural pearls are initiated in nature more or less by chance, but cultured pearls are human-initiated, formed by inserting a tissue graft from a donor mollusk, upon which a pearl sac forms, and the inner side precipitates calcium carbonate, in

975-643: Is a hard, glistening object produced within the soft tissue (specifically the mantle ) of a living shelled mollusk or another animal, such as fossil conulariids . Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite ) in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls , can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, pearl has become

1050-522: Is a particularly large one weighing 14 lb (6.4 kg). The largest known pearl (also from a giant clam) is the Pearl of Puerto , also found in the Philippines by a fisherman from Puerto Princesa , Palawan Island . The enormous pearl is 30 cm wide (1 ft), 67 cm long (2.2 ft) and weighs 75 lb (34 kg). The ancient chronicle Mahavamsa mentions the thriving pearl industry in

1125-402: Is caused by the overlapping of successive layers, which breaks up light falling on the surface. In addition, pearls (especially cultured freshwater pearls ) can be dyed yellow, green, blue, brown, pink, purple, or black. The most valuable pearls have a metallic, highly reflective luster. Because pearls are made primarily of calcium carbonate, they can be dissolved in vinegar . Calcium carbonate

1200-409: Is grown at a time. This limits the number of pearls at a harvest period. The pearls are usually harvested after one year for akoya , 2–4 years for Tahitian and South Sea, and 2–7 years for Edison. This perliculture process was first developed by British biologist William Saville-Kent , who passed the information along to Tatsuhei Mise and Tokichi Nishikawa from Japan . The second category includes

1275-459: Is grown at a time. This limits the number of pearls at a harvest period. The pearls are usually harvested after one year for akoya, 2–4 years for Tahitian and South Sea, and 2–7 years for freshwater. This perliculture process was first developed by the British biologist William Saville-Kent who passed the information along to Tatsuhei Mise and Tokichi Nishikawa from Japan . The second category includes

1350-445: Is made from layers of nacre , by the same living process as is used in the secretion of the mother of pearl which lines the shell. Natural (or wild) pearls, formed without human intervention, are very rare. Many hundreds of pearl oysters or mussels must be gathered and opened, and thus killed, to find even one wild pearl; for many centuries, this was the only way pearls were obtained, and why pearls fetched such extraordinary prices in

1425-549: Is more valuable than these pearls. However, it is more abundant than the South Sea pearl, which is more valuable than the black cultured pearl. This is simply because the black pearl oyster Pinctada margaritifera is far more abundant than the elusive, rare, and larger south sea pearl oyster Pinctada maxima , which cannot be found in lagoons, but which must be dived for in a rare number of deep ocean habitats or grown in hatcheries. Natural black pearls are rare, with black pearls having

1500-424: Is no bigger than 6 to 8 cm in size, hence akoya pearls larger than 10 mm in diameter are extremely rare and highly priced. Today, a hybrid mollusk is used in both Japan and China in the production of akoya pearls. Furthermore, other Pinctada and Pteria species are also used for producing cultured pearls today. The development of cultured pearls took much of the chance, risk, and guesswork out of

1575-415: Is required to positively verify natural pearls found today. A keshi pearl is a pearl composed entirely of nacre and results from mishaps in the culturing process. Most are quite small, typically only a few millimeters in diameter, and are often irregular in shape. In seeding a cultured pearl, a piece of mantle muscle from a sacrificed oyster is placed with a bead of mother of pearl within a host oyster. If

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1650-925: Is susceptible to even a weak acid solution because the crystals react with the acetic acid in the vinegar to form calcium acetate and carbon dioxide . Freshwater and saltwater pearls may sometimes look quite similar, but they come from different sources. Freshwater pearls form in various species of freshwater mussels, family Unionidae , which live in lakes, rivers, ponds and other bodies of fresh water. These freshwater pearl mussels occur not only in hotter climates, but also in colder, more temperate areas such as Scotland (where they are protected under law). Most freshwater cultured pearls sold today come from China. Saltwater pearls grow within pearl oysters, family Pteriidae , which live in oceans. Saltwater pearl oysters are usually cultivated in protected lagoons or volcanic atolls. The mollusk's mantle (protective membrane) deposits layers of calcium carbonate (CaCO 3 ) in

1725-618: Is the conch pearl (sometimes referred to simply as the 'pink pearl'), which is found very rarely growing between the mantle and the shell of the queen conch or pink conch, Strombus gigas , a large sea snail or marine gastropod from the Caribbean Sea . These pearls, which are often pink in color, are a by-product of the conch fishing industry, and the best of them display a shimmering optical effect related to chatoyance known as 'flame structure'. Somewhat similar gastropod pearls, this time more orange in hue, are (again very rarely) found in

1800-502: Is thought that natural pearls form under a set of accidental conditions when a microscopic intruder or parasite enters a bivalve mollusk and settles inside the shell. The mollusk, irritated by the intruder, forms a pearl sac of external mantle tissue cells and secretes the calcium carbonate and conchiolin to cover the irritant. This secretion process is repeated many times, thus producing a pearl. Natural pearls come in many shapes, with perfectly round ones being comparatively rare. Typically,

1875-516: The Broome area of Australia, while golden colored ones are more prevalent in the Philippines and Indonesia. A farm in the Gulf of California , Mexico, is culturing pearls from the black lipped Pinctada mazatlanica oysters and the rainbow lipped Pteria sterna oysters. Also called Concha Nácar, the pearls from these rainbow lipped oysters fluoresce red under ultraviolet light. Biologically speaking, under

1950-841: The Indian Ocean in areas such as the Persian Gulf , the Red Sea and the Gulf of Mannar . Evidence also suggest a prehistoric origin to pearl diving in these regions. Starting in the Han dynasty (206 BC–220 AD), the Chinese hunted extensively for seawater pearls in the South China Sea , particularly in what is now Tolo Harbour in Hong Kong . Tanka pearl divers of twelfth century China attached ropes to their waists in order to be safely brought back up to

2025-512: The Pearl Sac Theory (William Saville Kent, 1893) were all theories that tried to explain the pearls' formation. Mikimoto Kōkichi was able to use Nishikawa's technology. After the patent was granted in 1916, the technology was immediately commercially applied to akoya pearl oysters in Japan in 1916. Mise's brother was the first to produce a commercial crop of pearls in the akoya oyster. Mitsubishi 's Baron Iwasaki immediately applied

2100-437: The family Pteriidae . Freshwater pearls grow within certain (but by no means all) species of freshwater mussels in the order Unionida, the families Unionidae and Margaritiferidae . The unique luster of pearls depends upon the reflection , refraction , and diffraction of light from the translucent layers. The thinner and more numerous the layers in the pearl, the finer the luster. The iridescence that pearls display

2175-421: The gonad (reproductive organ) of a saltwater mollusk. In freshwater perliculture, only the piece of tissue is used in most cases, and is inserted into the fleshy mantle of the host bivalve. South Sea and Tahitian pearl oysters, as Pinctada maxima and Pinctada margaritifera , respectively, which survive the subsequent surgery to remove the finished pearl, are often implanted with a new, larger bead as part of

2250-468: The English name Margaret . All shelled mollusks can, by natural processes, produce some kind of "pearl" when an irritating microscopic object becomes trapped within its mantle folds, but the great majority of these "pearls" are not valued as gemstones . Nacreous pearls, the best-known and most commercially significant, are primarily produced by two groups of molluskan bivalves or clams . A nacreous pearl

2325-576: The Fifth Avenue mansion that is now the New York Cartier store in exchange for a matched double strand of natural pearls Cartier had been collecting for years; at the time, it was valued at US$ 1 million.) The introduction and advance of the cultured pearl hit the pearl industry hard. Pearl dealers publicly disputed the authenticity of these new cultured products, and left many consumers uneasy and confused about their much lower prices. Essentially,

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2400-519: The I.C.P. Canning Factory (International Pearl Company L.T.D.) in Nagasaki Pref. Japan. Cultured pearl Cultured pearls are pearls which are formed within a cultured pearl sac with human intervention in the interior of productive living molluscs in a variety of conditions depending upon the mollusc and the goals. Having the same material as natural pearls, cultured pearls can be cultivated in seawater or freshwater bodies. Over 95% of

2475-519: The King found it so beautiful that he kept it for himself. Later, he elevated it to be part of the Spanish Crown Jewel. From then on, the pearl was recorded in every royal inventory for more than 200 years. According to Garcilasso de la Vega , who says that he saw La Peregrina at Seville in 1607, this was found at Panama in 1560 by a slave worker who was rewarded with his liberty, and his owner with

2550-518: The attractions which drew Julius Caesar to Britain. They are, for the most part, freshwater pearls from mussels. Pearling was banned in the U.K. in 1998 due to the endangered status of river mussels. Discovery and publicity about the sale for a substantial sum of the Abernethy pearl in the River Tay had resulted in heavy exploitation of mussel colonies during the 1970s and 80s by weekend warriors. When it

2625-459: The bailer shell Melo , the giant clam Tridacna , various scallop species, Pen shells Pinna , and the Haliotis iris species of abalone. Pearls of abalone are cultured pearls , or blister pearls, unique to New Zealand waters, and are commonly referred to as 'blue pearls'. They are admired for their luster and naturally bright vibrant colors that are often compared to opal . Another example

2700-435: The build-up of a natural pearl consists of a brown central zone formed by columnar calcium carbonate (usually calcite, sometimes columnar aragonite) and a yellowish to white outer zone consisting of nacre (tabular aragonite). In a pearl cross-section such as the diagram, these two different materials can be seen. The presence of columnar calcium carbonate rich in organic material indicates juvenile mantle tissue that formed during

2775-487: The case. Typical stimuli include organic material, parasites, or even damage that displaces mantle tissue to another part of the mollusk's body. These small particles or organisms gain entry when the shell valves are open for feeding or respiration. In cultured pearls, the irritant is typically an introduced piece of the mantle epithelium, with or without a spherical bead (beaded or beadless cultured pearls). Natural pearls are nearly 100% calcium carbonate and conchiolin . It

2850-428: The conjunctive tissue of the mantle, these cells may survive and form a small pocket in which they continue to secrete calcium carbonate, their natural product. The pocket is called a pearl sac, and grows with time by cell division. The juvenile mantle tissue cells, according to their stage of growth, secrete columnar calcium carbonate from pearl sac's inner surface. In time, the pearl sac's external mantle cells proceed to

2925-458: The controversy damaged the images of both natural and cultured pearls. By the 1950s, when a significant number of women in developed countries could afford their own cultured pearl necklace, natural pearls were reduced to a small, exclusive niche in the pearl industry. Previously, natural pearls were found in many parts of the world. Present day natural pearling is confined mostly to the Persian Gulf , in seas off Bahrain . Australia also has one of

3000-503: The culturing process for them dictates a smaller volume output and they can never be mass-produced because, in common with most sea pearls, the oyster can only be nucleated with one pearl at a time, while freshwater mussels are capable of multiple pearl implants. Before the days of cultured pearls, black pearls were rare and highly valued for the simple reason that white pearl oysters rarely produced naturally black pearls, and black pearl oysters rarely produced any natural pearls at all. Since

3075-549: The development of pearl culture technology, the black pearl oysters Pinctada margaritifera found in Tahiti and many other Pacific islands including the Cook Islands and Fiji are being extensively used for producing cultured pearls. The rarity of the black cultured pearl is now a "comparative" issue. The black cultured pearl is rare when compared to Chinese freshwater cultured pearls, and Japanese and Chinese akoya cultured pearls, and

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3150-490: The early stage of pearl development. Displaced living cells with a well-defined task may continue to perform their function in their new location, often resulting in a cyst . Such displacement may occur via an injury. The fragile rim of the shell is exposed and is prone to damage and injury. Crabs, other predators and parasites such as worm larvae may produce traumatic attacks and cause injuries in which some external mantle tissue cells are disconnected from their layer. Embedded in

3225-512: The form of nacre or "mother-of-pearl". The most popular and effective method for creating cultured pearls utilizes the shells of freshwater river mussels harvested in the Midwestern U.S., from Canada to the Gulf of Mexico. Shells with the common names "Washboard", "Maple Leaf", "Ebony", "Pimpleback", and "Three Ridge" are popular for use in pearl culture due to their compatibility with the host animal and

3300-401: The form of the mineral aragonite or a mixture of aragonite and calcite (polymorphs with the same chemical formula, but different crystal structures) held together by an organic horn-like compound called conchiolin . The combination of aragonite and conchiolin is called nacre , which makes up mother-of-pearl. The commonly held belief that a grain of sand acts as the irritant is in fact rarely

3375-435: The formation of tabular aragonite. When the transition to nacre secretion occurs, the brown pebble becomes covered with a nacreous coating. During this process, the pearl sac seems to travel into the shell; however, the sac actually stays in its original relative position the mantle tissue while the shell itself grows. After a couple of years, a pearl forms and the shell may be found by a lucky pearl fisher. Cultured pearls are

3450-516: The horse conch Triplofusus papillosus . The second largest pearl known was found in the Philippines in 1934 and is known as the Pearl of Lao Tzu . It is a naturally occurring, non-nacreous, calcareous concretion (pearl) from a giant clam . Because it did not grow in a pearl oyster it is not pearly; instead the surface is glossy like porcelain. Other pearls from giant clams are known to exist, but this

3525-454: The host mussel. South Sea and Tahitian pearl oysters, also known as Pinctada maxima and Pinctada margaritifera , which survive the subsequent surgery to remove the finished pearl, are often implanted with a new, larger beads as part of the same procedure and then returned to the water for another 2–3 years of growth. Despite the common misperception, Mikimoto did not discover the process of pearl culture. The accepted process of pearl culture

3600-435: The largest and rarest of the cultured pearls – making them the most valuable. Prized for their exquisitely beautiful 'orient' or lustre, South Sea pearls are now farmed in various parts of the world where the Pinctada maxima oysters can be found, with the finest South Sea pearls being produced by Paspaley along the remote coastline of North-Western Australia. White and silver colored South Sea pearls tend to come from

3675-400: The last two years, large, near perfectly round, bead-nucleated pearls up to 15 mm in diameter with metallic luster have been produced. The nucleus bead in a beaded cultured pearl is generally a polished sphere made from freshwater mussel shell. Along with a small piece of mantle tissue from another mollusk (donor shell) to serve as a catalyst for the pearl sac, it is surgically implanted into

3750-478: The nacre they are to be covered by. These high-quality and sought-after shells are first sliced into strips and then into cubes. The edges and corners are ground down until they are a roughly spherical and then milled to become perfectly round, and brought to a highly polished finish. One of the first recorded histories of cultured pearls was found in the ancient China during the Song Dynasty. The cultivation method

3825-448: The non-beaded freshwater cultured pearls, like the Biwa or Chinese pearls. As they grow in the mantle, where on each wing up to 25 grafts can be implanted, these pearls are much more frequent and saturate the market completely. An impressive improvement in quality has taken place in the last 10 years, when the formerly rice grain-shaped pebbles are compared with the near round pearls of today. In

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3900-528: The non-beaded freshwater cultured pearls, like the Biwa or Chinese pearls. As they grow in the mantle, where on each wing up to 25 grafts can be implanted, these pearls are much more frequent and saturate the market completely. An impressive improvement in quality has taken place over ten years when the former rice-grain-shaped pebbles are compared with the near round pearls of today. Later, large near perfect round bead nucleated pearls up to 15mm in diameter have been produced with metallic luster. The nucleus bead in

3975-498: The office of alcalde of Panama. Margarita pearls are extremely difficult to find today and are known for their unique yellowish color. Before the beginning of the 20th century, pearl hunting was the most common way of harvesting pearls. Divers manually pulled oysters from ocean floors and river bottoms and checked them individually for pearls. Not all mussels and oysters produce pearls. In a haul of three tons, only three or four oysters will produce perfect pearls. Pearls were one of

4050-589: The past were also used to adorn clothing. They have also been crushed and used in cosmetics, medicines and paint formulations. Whether wild or cultured, gem-quality pearls are almost always nacreous and iridescent , like the interior of the shell that produces them. However, almost all species of shelled mollusks are capable of producing pearls (technically "calcareous concretions") of lesser shine or less spherical shape. Although these may also be legitimately referred to as "pearls" by gemological labs and also under U.S. Federal Trade Commission rules, and are formed in

4125-434: The past. Cultured pearls are formed in pearl farms, using human intervention as well as natural processes. One family of nacreous pearl bivalves – the pearl oyster  – lives in the sea, while the other – a very different group of bivalves  – lives in freshwater; these are the river mussels such as the freshwater pearl mussel . Saltwater pearls can grow in several species of marine pearl oysters in

4200-432: The pearl industry is making ongoing attempts to improve culturing technique so that keshi pearls do not occur. All-nacre pearls may one day be limited to natural found pearls. Today many "keshi" pearls are actually intentional, with post-harvest shells returned to the water to regenerate a pearl in the existing pearl sac. Tahitian pearls , frequently referred to as black pearls, are highly valued because of their rarity;

4275-400: The pearl industry, allowing it to become stable and predictable, and fostering its rapid growth over the past 100 years. Today, more than 99% of all pearls sold worldwide are cultured pearls. Colored pearls, which occur due to local chemicals inside the shell, much in the way of rubies or sapphires, can be made by inserting colored minerals into the mussel shell, e.g., cobalt chloride to create

4350-880: The pearls and the formation theory. Along the line of history and with the help of the Silk Road , Tiangong Kaiwu arrived in Europe and was translated. Scientists who were fascinated by the mysteries of pearls began their quest to find out how pearls are formed. From the 16th to the 18th century, the western world advanced in pearl research as new technologies, such as microscopes, developed. Scientists began more sophisticated research on pearl formation, developing new theories one after another. Disease Causation Theory (Guillaume Rondeletius, 1507 - 1566), Egg Causation Theory (Chauveton, 1578), Sand Grain Causation Theory (Sir R. Redding, 1674), Parasite Causation Theory (D. E. von Baer, 1830), and

4425-413: The pearls available on the market are cultured pearls. A pearl is formed when the mantle tissue is injured by a parasite, an attack of a fish, or another event that damages the external fragile rim of the shell of a mollusk shell bivalve or gastropod . In response, the mantle tissue of the mollusk secretes nacre into the pearl sac, a cyst that forms during the healing process. Chemically speaking, this

4500-403: The piece of mantle should slip off the bead, a keshi pearl forms of baroque shape about the mantle piece. Therefore, while a keshi pearl could be considered superior to cultured pearls with a mother of pearl bead center, in the cultured pearl industry the oyster's resources used to create a mistaken all-nacre baroque pearl is a drain on the production of the intended round cultured pearl. Therefore,

4575-555: The port of Oruwella in the Gulf of Mannar in Sri Lanka . It also records that eight varieties of pearls accompanied Prince Vijaya 's embassy to the Pandyan king as well as king Devanampiya Tissa 's embassy to Emperor Ashoka . Pliny the Elder (23–79 AD) praised the pearl fishery of the Gulf as most productive in the world. For thousands of years, seawater pearls were retrieved by divers in

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4650-404: The response of the shell to a tissue implant. A tiny piece of mantle tissue (called a graft ) from a donor shell is transplanted into a recipient shell, causing a pearl sac to form into which the tissue precipitates calcium carbonate. There are a number of methods for producing cultured pearls: using freshwater or seawater shells, transplanting the graft into the mantle or into the gonad, and adding

4725-486: The right set of circumstances, almost any shelled mollusk can produce some kind of pearl. However, most of these molluskan pearls have no luster or iridescence . The great majority of mollusk species produce pearls which are not attractive, and are sometimes not even very durable. Such pearls usually have no value at all, except perhaps to a scientist or collector, or as a curiosity. These objects used to be referred to as "calcareous concretions" by some gemologists, even though

4800-411: The same procedure, and then returned to the water for another 2–3 years of growth. An experimental process using a radio-frequency identification nucleus allows the provenance of cultured pearls to be tracked. A pearl nucleus or a bead for cultured pearl is a sphere (usually) or other shape (occasionally) formed only by cutting and polishing a nacreous shell used to accommodate the nacre secreted from

4875-549: The same way, most of them have no value except as curiosities. The English word pearl comes from the French perle , originally from the Latin perna ' leg ' , after the ham- or mutton leg-shaped bivalve . The scientific name for the family of pearl-bearing oysters, Margaritiferidae comes from the Old Persian word for pearl * margārīta- which is the source of

4950-433: The shape of the implanted shell bead nucleus. After a bead is inserted into the oyster, it secretes a few layers of nacre around the bead; the resulting cultured pearl can then be harvested in as few as twelve to eighteen months. When a cultured pearl with a bead nucleus is X-rayed, it reveals a different structure to that of a natural pearl. A beaded cultured pearl shows a solid center with no concentric growth rings, whereas

5025-541: The surface. When Spanish conquistadors arrived in the Western Hemisphere, they discovered that around the islands of Cubagua and Margarita , some 200 km north of the Venezuelan coast, was an extensive pearl bed (a bed of pearl oysters). One discovered and named pearl, La Peregrina pearl , was offered to Philip II of Spain who intended to give it as a gift for his daughter on the occasion of her marriage, but

5100-459: The technology to the South Sea pearl oyster in 1917 in the Philippines, and later in Buton and Palau . Mitsubishi was the first to produce a cultured South Sea pearl – although the first small commercial crop of pearls was not successfully produced until 1928. The original Japanese cultured pearls, known as akoya pearls, are produced by a species of small pearl oyster, Pinctada fucata , which

5175-682: The ten brothers come into contact with limestone, their powers disappear and they become helpless. The number of brothers varies among Chinese ethnicities: the Yi people have nine brothers; the Zhuang people have eight brothers; the Han people have five brothers; and the Li people have 10 brothers. The story has been adapted many times in Asian films and TV series, most notably in China and Hong Kong : Pearl A pearl

5250-810: The use of this X-ray technique. Natural and cultured pearls can be distinguished from imitation pearls using a microscope . Another method of testing for imitations is to rub two pearls against each other. Imitation pearls are completely smooth, but natural and cultured pearls are composed of nacre platelets, making both feel slightly gritty. Fine quality natural pearls are very rare jewels. Their values are determined similarly to those of other precious gems, according to size, shape, color, quality of surface, orient and luster. Single natural pearls are often sold as collectors' items, or set as centerpieces in unique jewelry. Very few matched strands of natural pearls exist, and those that do often sell for hundreds of thousands of dollars. (In 1917, jeweler Pierre Cartier purchased

5325-468: The world's last remaining fleets of pearl diving ships. Australian pearl divers dive for south sea pearl oysters to be used in the cultured south sea pearl industry. The catch of pearl oysters is similar to the numbers of oysters taken during the natural pearl days. Hence significant numbers of natural pearls are still found in the Australian Indian Ocean waters from wild oysters. X-ray examination

5400-543: Was developed by the British Biologist William Saville-Kent in Australia and brought to Japan by Tokichi Nishikawa and Tatsuhei Mise. Nishikawa was granted the patent in 1916, and married the daughter of Mikimoto. Mikimoto was able to use Nishikawa's technology. After the patent was granted in 1916, the technology was immediately commercially applied to akoya pearl oysters in Japan in 1916. Mise's brother

5475-661: Was permitted it was carried on mainly by Scottish Travellers who found pearls varied from river to river with the River Oykel in the Highlands being noted for the finest rose-pink pearls. There are two firms in Scotland that are licensed to sell pre-1998 freshwater pearls. Today, the cultured pearls on the market can be divided into two categories. The first category covers the beaded cultured pearls, including akoya, South Sea and Tahiti. These pearls are gonad grown, and usually one pearl

5550-527: Was the first to produce a commercial crop of pearls in the akoya oyster. Mitsubishi's Baron Iwasaki immediately applied the technology to the south sea pearl oyster in 1917 in the Philippines, and later in Buton, and Palau. Mitsubishi was the first to produce a cultured south sea pearl – although it was not until 1928 that the first small commercial crop of pearls was successfully produced. The original Japanese cultured pearls, known as akoya pearls, are produced by

5625-461: Was the same as the Mabe-pearl (half pearl) that we know of today. Instead of using the shells or saibo as the core, they used a mold to create a buddhist figure made from lead. The mold was then inserted into the freshwater mussel shell, Hyriopsis cumingii . In 1637, Mr. Song Yingxing compiled a Chinese encyclopedia called Tiangong Kaiwu ( 天工開物 ). Chapter 18 of this collection mentioned about

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