A pearl silver jewelry, sterling silver jewelry, gift ideas is a hard, roundish object produced within the soft tissue (specifically the mantle) of a living shelled mollusk silver jewelry, sterling silver jewelry, gift ideas . Just like the shell of mollusks, a pearl is composed of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes of pearls (baroque pearls) occur silver jewelry, sterling silver jewelry, gift ideas

The finest quality pearls have been highly valued as gemstones and objects of beauty silver jewelry, sterling silver jewelry, gift ideas for many centuries, and the word pearl has become a metaphor for something rare, fine, and admirable silver jewelry, sterling silver jewelry, gift ideas

Almost any shelled mollusk can, by natural processes, produce some kind of "pearl" when an irritating microscopic object becomes trapped within the mollusk's mantle folds, but virtually none of these "pearls" are valued as gemstones silver jewelry, sterling silver jewelry, gift ideas

Nacreous pearls, the most desirable pearls, are produced by two groups of molluscan bivalves or clams. silver jewelry, sterling silver jewelry, gift ideas One family lives in the sea: the pearl oysters. The other, very different group of bivalves live in freshwater, and these are the river mussels; for example, see the freshwater pearl mussel silver jewelry, sterling silver jewelry, gift ideas

Saltwater pearls can grow in several species of marine pearl oysters in the family Pteriidae silver jewelry, sterling silver jewelry, gift ideas . Freshwater pearls grow within certain (but by no means all) species of freshwater mussels in the order Unionida, the families Unionidae and Margaritiferidae. These various species of bivalves are able to make nacreous pearls because they have a thick iridescent inner shell layer called "mother of pearl", which is composed of nacre. The mantle tissue of a living bivalve can create a pearl in the same manner that it creates the pearly inner layer of the shell. silver jewelry, sterling silver jewelry, gift ideas

Fine gem-quality saltwater and freshwater pearls can and do sometimes occur completely naturally, but this is rare. Many hundreds of pearl oysters or pearl mussels have to be gathered and opened, and thus killed, in order to find even one pearl, and for many centuries that was the only way pearls were obtained silver jewelry, sterling silver jewelry, gift ideas . This was the main reason why pearls fetched such extraordinary prices in the past. In modern times however, almost all the pearls for sale were formed with a good deal of expert intervention from human pearl farmers silver jewelry, sterling silver jewelry, gift ideas.

A nacreous pearl is made from layers of nacre, by the same living process as is used in the secretion of the mother of pearl silver jewelry, sterling silver jewelry, gift ideas which lines the shell. A "natural pearl" is one that formed without any human intervention at all, in the wild, and is very rare. A "cultured pearl", on the other hand, is one that has been formed on a pearl farm. The great majority of pearls on the market are cultured pearls silver jewelry, sterling silver jewelry, gift ideas.

Imitation or fake pearls are also widely sold in inexpensive jewelry, but the quality of the iridescence is usually very poor, and generally speaking, fake pearls are usually quite easy to distinguish from the real thing.

Pearls have been harvested, or more recently cultivated, primarily for use in jewelry, but in the past they were also stitched onto lavish clothing, as worn, for example, by royalty. Pearls have also been crushed and used in cosmetics, medicines, or in paint formulations.

Pearl is considered to be the birthstone for June silver jewelry, sterling silver jewelry, gift ideas.

Physical properties

Pearls are often white or cream, but the color can vary quite a lot according to the natural color of the nacre in the various species of mollusk used. Thus pearls can also be black, or various pastel shades. In addition, pearls silver jewelry, sterling silver jewelry, gift ideas (especially freshwater pearls) can be dyed yellow, green, blue, brown, pink, purple, or black silver jewelry, sterling silver jewelry, gift ideas.

Freshwater and saltwater pearls

silver jewelry, sterling silver jewelry, gift ideas  Freshwater and saltwater pearls silver jewelry, sterling silver jewelry, gift ideas may sometimes look quite similar, but they come from very different sources silver jewelry, sterling silver jewelry, gift ideas.

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. However, most freshwater cultured pearls sold today come from China silver jewelry, sterling silver jewelry, gift ideas   .

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 three main types of saltwater pearls are akoya, South Sea and Tahitian.

Creation of a pearl

The difference between natural and cultured pearls focuses on whether the pearl was created spontaneously by nature — without human intervention — or with human aid. Pearls are formed inside the shell of certain mollusks: as a defense mechanism to a potentially threatening irritant such as a parasite inside its shell, the mollusk creates a pearl to seal off the irritation.

The mantle of the mollusk deposits layers of calcium carbonate (CaCO₃) in the form of the minerals aragonite or a mixture of aragonite and calcite (both crystalline forms of calcium carbonate) held together by an organic horn-like compound called conchiolin. The combination of aragonite and conchiolin is called nacre, which makes up mother-of-pear. The commonly held belief that a grain of sand acts as the irritant is in fact rarely the case. Typical stimuli include organic material, parasites, or even damage that displaces mantle tissue to another part of the animal's body. These small particles or organisms enter the animal when the shell valves are open for feeding or respiration. In cultured pearls, the irritant is typically a cut piece of the mantle epithelium, together with processed shell beads, the combination of which the animal accepts into its body.

Natural pearls

Natural pearls are nearly 100% calcium carbonate and conchiolin. It 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, being irritated by the intruder, 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 round ones being comparatively rare.

Cultured pearls

Cultured pearls (nucleated and non-nucleated or tissue nucleated cultured pearls) and imitation pearls can be distinguished from natural pearls by X-ray examination. Nucleated cultured pearls are often 'pre-formed' as they tend to follow the shape of the implanted shell bead nucleus. Once the pre-formed beads are inserted into the oyster, it secretes a few layers of nacre around the outside surface of the implant before it is removed after six months or more. When a nucleated cultured pearl is X-rayed it will reveal a different structure to that of a natural pearl. It exhibits a solid center with no concentric growth rings, compared to a solid center with growth rings.

Gemological identification

A well equipped gem testing laboratory is able to distinguish natural pearls from cultured pearls by using a gemological x-ray in order to examine the center of a pearl. With an x-ray 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 a natural pearls from or tissue-nucleated cultured pearls can be very difficult without the use of this x-ray technique silver jewelry, sterling silver jewelry, gift ideas.

Natural and cultured pearls can be distinguished from imitation pearls using a microscope. Another method of testing for imitations is to rub the pearl against the surface of a front tooth. Imitation pearls are completely smooth, but natural and cultured pearls are composed of nacre platelets, which feel slightly gritty.

Value of a natural pearl

Quality natural pearls are very rare jewels. The actual value of a natural pearl is determined in the same way as it would be for other "precious" gems. The valuation factors include size, shape, quality of surface, orient and luster silver jewelry, sterling silver jewelry, gift ideas.

Single natural pearls are often sold as a collector's item, 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. Yachtsman and financier Cartier purchased the landmark Cartier store on Fifth Avenue in New York for $100 cash and a double strand of matched natural pearls valued at $1 million.

Keshi pearls, although they often occur by chance, are not considered natural pearls. They are a byproduct of the culturing process, and hence do not happen without human intervention. These pearls are quite small: typically a few millimeters in size. Keshi pearls are produced by many different types of marine mollusks and freshwater mussels in China. Today many "keshi" pearls are actually intentional, with post-harvest shells returned to the water to regenerate a pearl in the existing pearl sac.

Origin of a natural pearl

Previously natural pearls were found in many parts of the world. Present day natural pearling is confined mostly to seas off Bahrain. Australia also has one of 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. silver jewelry, sterling silver jewelry, gift ideas 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 is required to positively verify natural pearls found today.

Different types of cultured pearls

Other "pearls"

Biologically speaking, under the right set of circumstances, almost any shelled mollusk can produce some kind of "pearl," however, most of these molluscan "pearls" have no luster or iridescence. In fact the great majority of mollusk species produce pearls which are not attractive to look at, and are sometimes not even very durable, such that they usually have no value at all, except perhaps to a scientist, a collector, or as a curiosity. These objects would be referred to as "calcareous concretions" by a gemologist, even though a malacologist would still consider them to be pearls.

One unusual example of calcareous concretions which nonetheless can sometimes have value, are the "pearls" which are 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 pink in color, are a by-product of the conch fishing industry, and the best of them show some chatoyance.

Somewhat similar gastropod "pearls", this time more orange in hue, are (again very rarely) found in the horse conch Pleuroploca gigantea.

Largest example of a "pearl" from another mollusk species

The largest "pearl" known, was found in the Philippines in 1934. It is a naturally-occurring, non-nacreous, calcareous concretion from a giant clam. Because it did not grow in a pearl oyster it is not pearly, instead it has a porcellaneous surface. In other words, it is glossy like a china plate. Gemologically speaking, it is not a pearl. Other "pearls" from giant clams are known to exist, but this is a particularly large one silver jewelry, sterling silver jewelry, gift ideas.

The "pearl" weighs 14 lb (6.4 kg) and was supposedly first discovered by an anonymous Filipino Muslim diver off the island of Palawan in 1934. According to the legend as it is currently told, a Palawan chieftain gave the pearl to Wilbur Dowell Cobb in 1936 as a gift for having saved the life of his son. The pearl had been named the "Pearl of Allah" by the Muslim tribal chief, because it resembled a turbaned head. Another even more elaborate legend says that this object is actually the Pearl of Lao-Tzu, a cultured pearl created with a carved amulet and then supposedly progressively grafted into several giant clams, before supposedly being lost due to a shipwreck in 1745. This legend has been discredited, however because this "pearl" is indeed the product of a giant clam, Tridacna gigas, which cannot be grafted. The "pearl" is also a whole pearl, not a mabe pearl, and whole pearl culturing technology is only 100 years old.

The history of pearl hunting and pearl farming

Pearl hunting

For thousands of years, most seawater pearls were retrieved by divers working in the Indian Ocean, in areas like the Persian Gulf, the Red Sea, and in the Gulf of Mannar (by the ancient Tamils).

Starting in the Han Dynasty (206 BC - 220 AD), the Chinese hunted extensively for seawater pearls in the South China Sea.

Margarita pearls are extremely difficult to find today and are known for their unique yellowish color. The most famous Margarita necklace that any one can see today is the one that then Venezuelan President Romulo Betancourt gave to Jacqueline Kennedy when she and her husband, President John F. Kennedy paid an official visit to Venezuela.

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.

The development of pearl farming

Today, almost all pearls used for jewelry are cultured by planting a core or nucleus into pearl oysters. 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 William Sawville-Kent who passed the information along to Tatsuhei Mise and Tokichi Nishikawa from Japan.

The nucleus is generally a polished bead made from freshwater mussel shell. Along with a small piece of mantle tissue from another mollusk 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 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 nucleus 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 was developed by William Sawville-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 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 a species of small pearl oyster, Pinctada fucata martensii, which is no bigger than 6 to 8 cm in size, hence akoya pearls larger than 10 mm in diameter are extremely rare and highly prized. Today, a hybrid mollusk is used in both Japan and China in the production of akoya pearls. It is a cross between the original Japanese species, and the Chinese species Pinctada chemnitzii.

Recent pearl production

China has recently overtaken Japan in akoya pearl production. Japan has all but ceased its production of akoya pearls smaller than 8 mm. Japan maintains its status as a pearl processing center, however, and imports the majority of Chinese akoya pearl production. These pearls are then processed (often simply matched and sorted), relabeled as product of Japan, and exported.

In the past couple of decades, cultured pearls have been produced using larger oysters in the south Pacific and Indian Ocean. The largest pearl oyster is the Pinctada maxima, which is roughly the size of a dinner plate. South Sea pearls are characterized by their large size and silvery color. Sizes up to 14 mm in diameter are not uncommon. Australia is one of the most important sources of South Sea pearls silver jewelry, sterling silver jewelry, gift ideas.

Mitsubishi commenced pearl culture with the south sea pearl oyster in 1916, as soon as the technology patent was commercialized. By 1931 this project was showing signs of success, but was upset by the death of Tatsuhei. Although the project was recommenced after Tatsuhei's death, the project was discontinued at the beginning of WWII before significant productions of pearls were achieved.

After WWII, new south sea pearl projects were commenced in the early 1950s in Burma and Kuri Bay and Port Essington in Australia. Japanese companies were involved in all projects using technicians from the original Mitsubishi south sea pre-war projects. Despite often being described as black south sea pearls, Tahitian pearls are not in fact south sea pearls. The correct definition of a south sea pearl is a "pearl produced by the Pinctada maxima pearl oyster."

Japanese freshwater pearl farming

In 1914, pearl farmers began culturing freshwater pearls using the pearl mussels native to Lake Biwa. This lake, the largest and most ancient in Japan, lies near the city of Kyoto. The extensive and successful use of the Biwa Pearl Mussel is reflected in the name Biwa pearls, a phrase which was at one time nearly synonymous with freshwater pearls in general. Since the time of peak production in 1971, when Biwa pearl farmers produced six tons of cultured pearls, pollution and overharvesting have caused the virtual extinction of this animal. Japanese pearl farmers recently cultured a hybrid pearl mussel — a cross between Biwa Pearl Mussels and a closely related species from China, "Hyriopsis cumingi, in lake Kasumigaura. This industry has nearly ceased production due to lake pollution.

Japanese pearl producers also invested in producing cultured pearls with freshwater mussels in the region of Shanghai, China. China has since become the world's largest producer of freshwater pearls, producing more than 1,500 metric tons per year.

Led by pearl pioneer John Latendresse and his wife Chessy, the United States began farming freshwater cultured pearls in the mid 1960's. National Geographic Magazine introduced the American cultured pearl as a commercial product in their August 1985 issue. The Tennessee pearl farm has emerged as a tourist destination in recent years, but commercial production of freshwater pearls has ceased.

Pearls in jewelry

Some imitation pearls are simply made of mother-of-pearl, coral or conch, while others are made from glass and are coated with a solution containing fish scales called essence d'Orient. Although imitation pearls look the part, they do not have the same weight or smoothness as real pearls, and their luster will also dim greatly.

There is also a unique way of naming pearl necklaces. While most other necklaces are simply referred to by their physical measurement, strings of pearls have their own set of names that characterize the pearls based on where they hang when worn around the neck. A collar will sit directly against the throat and not hang down the neck at all; they are often made up of multiple strands of pearls. Pearl chokers nestle just at the base of the neck. The size called a princess comes down to or just below the collarbone. A matinee of pearls falls just above the breasts. An opera will be long enough to reach the breastbone or sternum of the wearer, and longer still, a pearl rope is any length that falls down farther than an opera.

Necklaces can also be classified as uniform, or graduated. In a uniform strand of pearls, all pearls are classified as the same size, but actually fall in a range. A uniform strand of akoya pearls, for example, will measure within 0.5 mm. So a strand will never be 7 mm, but will be 6.5-7 mm. Freshwater pearls, Tahitian pearls, and South Sea pearls all measure to a full millimeter when considered uniform. A graduated strand of pearls most often has at least 3 mm of differentiation from the ends to the center of the necklace. Popularized in the 1950s by the GIs bringing strands of cultured akoya pearls home from Japan, the graduated style was much more affordable as most pearls in any given strand were small.

Earrings and necklaces can also be classified on the grade of the color of the pearl. While white and more recently black pearls are by far the most popular colors, other tinges of color can be found on pearls. Pink, blue, champagne, green and even purple can be found, but to form a complete string of same size and shade pearls can take years.

Religious references

According to Rebbenu Bachya, the word Yahalom in the verse Exodus 28:18 means "pearl" and was the stone on the Hoshen representing the tribe of Zebulun. This is extremely disputed among scholars, particularly since the word in question in most manuscripts is actually Yasepheh - the word from which jasper derives; scholars think that refers to green jasper (the rarest and most prize form in early times) rather than red jasper (the most common form). Yahalom is usually translated by the Septuagint as an "onyx", but sometimes as "beryl" or as "jasper"; onyx only started being mined after the Septuagint was written, so the Septuagint's term "onyx" probably does not mean onyx - onyx is originally an Assyrian word meaning ring, and so could refer to anything used for making rings. Yahalom is similar to a Hebrew word meaning hit hard, so some people think that it means diamond. The variation in possibilities of meaning for this sixth stone in the Hoshen is reflected in different translations of the Bible — the King James Version translates the sixth stone as diamond, the New International Version translates it as emerald, and the Vulgate translates it as jaspis — meaning jasper. There is a wide range of views among traditional sources about which tribe the stone refers to.

In a Christian New Testamet, parable, Jesus compared the Kingdom of Heaven to a "pearl of great price" in Matthew 13: 45-46. "Again, the kingdom of heaven is like unto a merchant man, seeking goodly pearls: Who, when he had found one pearl of great price, went and sold all that he had, and bought it."

The language of symbolism was in common use around the time of Jesus Christ and most people knew this language. The circle is a symbol of God, it has no beginning and no end. The circle or pearl was considered to represent Love, Knowledge (the combination of equal amounts of Love and Knowledge is a symbol of Wisdom, the 2 circles intertwined (owl eyes) is symbolic of Wisdom. Some other pearls are Truth, and Faith.

The Pearl of Great Price is a book of scripture in The Church of Jesus Christ of Latter-day Saints.

The twelve gates of the New Jerusalem are reportedly each made of a single pearl in Revelation 21:21, that is, the Pearly Gates. "And the twelve gates were twelve pearls; every gate was of one pearl: and the streets of the city were pure gold, as if transparent glass."

Pearls are compared to holy things, in Matthew 7: 6. "Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you."

Pearls are also found in numerous references showing the wickedness and pride of a people, as in Revelations 18: 16. "And saying, Alas, alas, that great city, that was clothed in fine linen, and purple, and scarlet, and decked with gold, and precious stones, and pearls!"

The metaphor of a pearl appears in the longer Hymn of the Pearl, a poem respected for its high literary quality, and use of layered theological metaphor, found within one of the texts of Gnosticism.

Islamic references

In Islam, the Koran often mentions that dwellers of paradise will be adorned with pearls:

22:23 God will admit those who believe and work righteous deeds, to Gardens beneath which rivers flow: they shall be adorned therein with bracelets of gold and pearls; and their garments there will be of silk.

35:33 Gardens of Eternity will they enter: therein will they be adorned with bracelets of gold and pearls; and their garments there will be of silk.

The Quran describes the wives of the people of Paradise as having eyes that are similar to pearls:

56:22-23 And [there will be] Houris with wide lovely eyes [as wives for the pious], Like unto preserved pearls.

The handsome young boys in paradise are similarly depicted:

52:24 Round about them will serve, [devoted] to them, youths [handsome] as pearls well-guarded.

Hindu astrological belief in natural pearls

The Vedic tradition describes the sacred Nine Pearls which were first documented in the Garuda Purana, one of the books of the Hindu holy text Atharvaveda. Ayurveda contains references to pearl powder as a stimulant of digestion and to treat mental ailments. According to Marco Polo the kings of Malabar (now known as the Coromandel Coast) wore a necklace of 104 rubies and 104 precious pearls which was given from one generation of kings to the next. The reason was that every king had to say 104 prayers to his "idols" every morning and every evening. At least until the beginning of the 20th century it was a Hindu custom to present a completely new, undrilled pearl and pierce it during the ceremony.