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A pearl is a hard, glistening object produced within the soft tissue (specifically the
mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...
) of a living
shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard ou ...
ed
mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000  extant species of molluscs are recognized. The number of fossil species is e ...
or another animal, such as fossil
conulariid Conulariida is a poorly understood fossil group that has possible affinity with the Cnidaria. Their exact position as a taxon of extinct medusozoan cnidarians is highly speculative. Members of the Conulariida are commonly referred to as conularii ...
s. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly
aragonite Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including prec ...
or a mixture of aragonite and
calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...
) 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 Baroque pearls are pearls with an irregular, non-spherical shape. Shapes can range from minor aberrations to distinctly ovoid, curved, pinched, or lumpy shapes. Most cultured freshwater pearls are baroque because freshwater pearls are mantle-tis ...
, can occur. The finest quality of natural pearls have been highly valued as
gemstone A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, ...
s and objects of
beauty Beauty is commonly described as a feature of objects that makes these objects pleasurable to perceive. Such objects include landscapes, sunsets, humans and works of art. Beauty, together with art and taste, is the main subject of aesthetics, o ...
for many centuries. Because of this, ''pearl'' has become a
metaphor A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are often compared wit ...
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 oyster ''Pinctada'' is a genus of saltwater oysters, marine bivalve mollusks in the family Pteriidae. These pearl oysters have a strong inner shell layer composed of nacre, also known as "mother of pearl". Pearl oysters are not closely related to ei ...
s and freshwater mussels make up the majority of those currently sold.
Imitation pearl Imitation pearls are man-made ''faux'' pearls. They are not to be confused with cultured pearls, which are real pearls created through artificial intervention. Materials used to create imitation pearls include glass, plastic, and mollusc shells ...
s are also widely sold in inexpensive jewelry. Pearls have been harvested and cultivated primarily for use in
jewelry Jewellery ( UK) or jewelry (U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western ...
, but in 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
nacre Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is f ...
ous and
iridescent Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...
, 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 The Federal Trade Commission (FTC) is an independent agency of the United States government whose principal mission is the enforcement of civil (non-criminal) antitrust law and the promotion of consumer protection. The FTC shares jurisdiction ov ...
rules, and are formed in the same way, most of them have no value except as curiosities.


Etymology

The
English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...
word ''pearl'' comes from the
French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...
''perle'', originally from the
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''perna'' meaning leg, after the ham- or mutton leg-shaped
bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
. The scientific name for the family of pearl-bearing oysters,
Margaritiferidae Margaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve molluscs in the order Unionida. Text may have been copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. It is the m ...
comes from the
Old Persian Old Persian is one of the two directly attested Old Iranian languages (the other being Avestan language, Avestan) and is the ancestor of Middle Persian (the language of Sasanian Empire). Like other Old Iranian languages, it was known to its native ...
word for pearl ''*margārīta-'' which is the source of the English name
Margaret Margaret is a female first name, derived via French () and Latin () from grc, μαργαρίτης () meaning "pearl". The Greek is borrowed from Persian. Margaret has been an English name since the 11th century, and remained popular througho ...
.


Definition

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 A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, an ...
. Nacreous pearls, the best-known and most commercially significant, are primarily produced by two groups of molluskan
bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
s or
clam Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two she ...
s. A nacreous pearl is made from layers of
nacre Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is f ...
, by the same living process as is used in the secretion of the
mother of pearl Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is ...
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 the past.
Cultured pearl Cultured pearls 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. Just as the same as natural pearls, cultured pearls ...
s are formed in pearl farms, using human intervention as well as natural processes. One family of nacreous pearl bivalves – the
pearl oyster ''Pinctada'' is a genus of saltwater oysters, marine bivalve mollusks in the family Pteriidae. These pearl oysters have a strong inner shell layer composed of nacre, also known as "mother of pearl". Pearl oysters are not closely related to ei ...
 – lives in the sea, while the other – a very different group of
bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
s – lives in freshwater; these are the river
mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...
s such as the
freshwater pearl mussel The freshwater pearl mussel (''Margaritifera margaritifera'') is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae. Although the name "freshwater pearl mussel" is often used for this species ...
. Saltwater pearls can grow in several species of
marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...
pearl
oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...
s in the
family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Pteriidae Pteriidae, also called the feather oysters, is a family of medium-sized to large saltwater clams. They are pearl oysters, marine bivalve molluscs in the order Pteriida. Some of the species in this family are important economically as the sou ...
. Freshwater pearls grow within certain (but by no means all) species of freshwater mussels in the order Unionida, the families
Unionidae The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is at its most diverse ...
and
Margaritiferidae Margaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve molluscs in the order Unionida. Text may have been copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. It is the m ...
.


Physical properties

The unique luster of pearls depends upon the
reflection Reflection or reflexion may refer to: Science and technology * Reflection (physics), a common wave phenomenon ** Specular reflection, reflection from a smooth surface *** Mirror image, a reflection in a mirror or in water ** Signal reflection, in s ...
,
refraction In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomeno ...
, and
diffraction Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a s ...
of light from the
translucent In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions a ...
layers. The thinner and more numerous the layers in the pearl, the finer the luster. The
iridescence Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...
that pearls display is caused by the overlapping of successive layers, which breaks up light falling on the surface. In addition, pearls (especially
cultured freshwater pearls Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Comm ...
) 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 Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to et ...
. Calcium carbonate is susceptible to even a weak acid solution because the crystals react with the
acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
in the vinegar to form
calcium acetate Calcium acetate is a chemical compound which is a calcium salt of acetic acid. It has the formula Ca(C2H3O2)2. Its standard name is calcium acetate, while calcium ethanoate is the systematic name. An older name is acetate of lime. The anhydrous ...
and
carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
.


Freshwater and saltwater pearls

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 The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is at its most diverse ...
, which live in lakes, rivers, ponds and other bodies of fresh water. These
freshwater pearl mussel The freshwater pearl mussel (''Margaritifera margaritifera'') is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae. Although the name "freshwater pearl mussel" is often used for this species ...
s occur not only in hotter climates, but also in colder more temperate areas such as
Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...
(where they are protected under law). Most freshwater
cultured pearl Cultured pearls 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. Just as the same as natural pearls, cultured pearls ...
s sold today come from China. Saltwater pearls grow within pearl oysters, family
Pteriidae Pteriidae, also called the feather oysters, is a family of medium-sized to large saltwater clams. They are pearl oysters, marine bivalve molluscs in the order Pteriida. Some of the species in this family are important economically as the sou ...
, which live in oceans. Saltwater
pearl oyster ''Pinctada'' is a genus of saltwater oysters, marine bivalve mollusks in the family Pteriidae. These pearl oysters have a strong inner shell layer composed of nacre, also known as "mother of pearl". Pearl oysters are not closely related to ei ...
s are usually cultivated in protected
lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...
s or volcanic atolls.


Creation

The mollusk's mantle (protective membrane) deposits layers of calcium carbonate (CaCO3) in the form of the
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
aragonite Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including prec ...
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 Conchiolins (sometimes referred to as conchins) are complex proteins which are secreted by a mollusc's outer epithelium (the mantle). These proteins are part of a matrix of organic macromolecules, mainly proteins and polysaccharides, that assem ...
. The combination of aragonite and conchiolin is called
nacre Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is f ...
, which makes up mother-of-pearl. 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 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

Natural pearls are nearly 100% calcium carbonate and
conchiolin Conchiolins (sometimes referred to as conchins) are complex proteins which are secreted by a mollusc's outer epithelium (the mantle). These proteins are part of a matrix of organic macromolecules, mainly proteins and polysaccharides, that assem ...
. 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, 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, 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 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 A cyst is a closed sac, having a distinct envelope and cell division, division compared with the nearby Biological tissue, tissue. Hence, it is a cluster of Cell (biology), cells that have grouped together to form a sac (like the manner in which ...
. 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 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 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

Cultured pearls are 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 a spherical bead as a nucleus. Most saltwater cultured pearls are grown with beads. Trade names of cultured pearls are Akoya (), 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 An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10  picometers to 10  nanometers, corresponding to frequencies in the range 30&nb ...
examination. Nucleated cultured pearls are often 'preformed' as they tend to follow 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 (see diagram). A beaded cultured pearl shows a solid center with no concentric growth rings, whereas 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.


Imitation pearls

Some imitation pearls (also called shell pearls) are simply made of
mother-of-pearl Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is f ...
,
coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...
or
conch Conch () is a common name of a number of different medium-to-large-sized sea snails. Conch shells typically have a high spire and a noticeable siphonal canal (in other words, the shell comes to a noticeable point at both ends). In North Am ...
shell, while others are made from glass and are coated with a solution containing fish scales called ''essence d'Orient''.


Gemological identification

A well-equipped gem testing laboratory can distinguish natural pearls from cultured pearls by using gemological
X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10  picometers to 10  nanometers, corresponding to frequencies in the range 30&nb ...
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 the use of this X-ray technique. Natural and
cultured pearl Cultured pearls 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. Just as the same as natural pearls, cultured pearls ...
s can be distinguished from imitation pearls using a
microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
. 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.


Value of a natural pearl

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 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, 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.


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 Bahrain ( ; ; ar, البحرين, al-Bahrayn, locally ), officially the Kingdom of Bahrain, ' is an island country in Western Asia. It is situated on the Persian Gulf, and comprises a small archipelago made up of 50 natural islands and an ...
. 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. 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.


Types of cultured pearls

A
keshi pearl Keshi pearls are small non-nucleated pearls typically formed as by-products of pearl cultivation. A Japanese word also meaning "poppy" (ケシ, 芥子), it is used in Japanese for all pearls that grew without a nucleus. Originally, keshi pearls r ...
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 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, 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 pearl The Tahitian pearl (or black pearl) is an organic gem formed from the black lip oyster ('' Pinctada margaritifera'').Newman, Renee. ''Pearl Buying Guide''. "Black Pearls." Los Angeles: International Jewelry Publications, c2005, p. 73 These pearls d ...
s, frequently referred to as black pearls, are highly valued because of their rarity; 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 the development of pearl culture technology, the black pearl oysters ''Pinctada margaritifera'' found in
Tahiti Tahiti (; Tahitian ; ; previously also known as Otaheite) is the largest island of the Windward group of the Society Islands in French Polynesia. It is located in the central part of the Pacific Ocean and the nearest major landmass is Austr ...
and many other Pacific islands including the
Cook Islands ) , image_map = Cook Islands on the globe (small islands magnified) (Polynesia centered).svg , capital = Avarua , coordinates = , largest_city = Avarua , official_languages = , lan ...
and
Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...
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 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 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 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 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 Paspaley, officially the Paspaley Pearling Company, a private company, is Australia's largest and oldest pearling company; that cultivates, farms, harvests, wholesales and retails South Sea pearls for the purposes of luxury jewellery supply a ...
along the remote coastline of North-Western Australia. White and silver colored South Sea pearls tend to come from the Broome area of Australia, while golden colored ones are more prevalent in the Philippines and Indonesia. A farm in the
Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...
, 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 Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
light.


From other species

Biologically speaking, under 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 Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...
. 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 a
malacologist Malacology is the branch of invertebrate zoology that deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, ...
would still consider them to be pearls. Valueless pearls of this type are sometimes found in edible
mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...
s, edible
oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...
s,
escargot Snails are considered edible in many areas such as the Mediterranean region, Africa, or Southeast Asia, while in other cultures, snails are seen as a taboo food. In American English, edible land snails are also called escargot, taken from the Fren ...
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 the bailer shell '' Melo'', the
giant clam The giant clams are the members of the clam genus ''Tridacna'' that are the largest living bivalve mollusks. There are actually several species of "giant clams" in the genus ''Tridacna'', which are often misidentified for ''Tridacna gigas'', th ...
''Tridacna'', various
scallop Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families ...
species, Pen shells '' Pinna'', and the ''
Haliotis iris ''Haliotis iris'', common name paua, blackfoot paua or rainbow abalone, is a species of edible sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones.Bouchet, P. (2014). Haliotis iris. Accessed through: World Register of Mar ...
'' species of abalone. Pearls of abalone, or paua, are mabe pearls, or blister pearls, unique to
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
waters and are commonly referred to as 'blue pearls'. They are admired for their incredible luster and naturally bright vibrant colors that are often compared to
opal Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms ...
. Another example 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 Conch () is a common name of a number of different medium-to-large-sized sea snails. Conch shells typically have a high spire and a noticeable siphonal canal (in other words, the shell comes to a noticeable point at both ends). In North Am ...
or pink conch, ''
Strombus gigas ''Aliger gigas,'' originally known as ''Strombus gigas'' or more recently as ''Lobatus gigas'', commonly known as the queen conch, is a species of large sea snail, a marine gastropod mollusc in the family of true conches, the Strombidae. This ...
'', a large sea snail or marine
gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
from the
Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...
. 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 In gemology, chatoyancy ( ), or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones, woods, and carbon fibre. Coined from the French "œil de chat", meaning "cat's eye", chatoyancy arises either from the ...
known as 'flame structure'. Somewhat similar gastropod pearls, this time more orange in hue, are (again very rarely) found in the horse conch ''
Triplofusus papillosus ''Triplofusus giganteus'', previously known as ''Pleuroploca gigantea'', common name the Florida horse conch, is a species of extremely large predatory subtropical and tropical sea snail, a marine gastropod mollusc in the family Fasciolariidae, t ...
''. The second largest pearl known was found in the
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
in 1934 and is known as the ''
Pearl of Lao Tzu The Pearl of Lao Tzu (also referred to as Pearl of Lao Tze) was once considered the largest known pearl. The pearl was found in the Palawan sea, which surrounds the island of Palawan in the Philippines, and was found by a Filipino diver. It is not ...
''. It is a naturally occurring, non-nacreous, calcareous concretion (pearl) from a
giant clam The giant clams are the members of the clam genus ''Tridacna'' that are the largest living bivalve mollusks. There are actually several species of "giant clams" in the genus ''Tridacna'', which are often misidentified for ''Tridacna gigas'', th ...
. 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 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 Pearl of Puerto, also referred to as Pearl of Puerto Princesa ( fil, Perlas ng Puerto) was found in the Philippine Sea by a Filipino fisherman. It measures 2.2 feet (67 cm) long, 1 foot (30 cm) wide and weighs 34 kilograms (75 lb). ...
, also found in the Philippines by a fisherman from
Puerto Princesa Puerto Princesa, officially the City of Puerto Princesa (Cuyonon: ''Siyudad i'ang Puerto Princesa''; fil, Lungsod ng Puerto Princesa), is a 1st class highly urbanized city in the Mimaropa region of the Philippines. According to the 2020 census, ...
,
Palawan Island Palawan is the largest island of the province of Palawan in the Philippines and fifth-largest by area and tenth-most populous island of the country, with a total population of 994,101 as of 2020 census. The north west coast of the island is alon ...
. The enormous pearl is 30 cm wide (1 ft), 67 cm long (2.2 ft) and weighs 75 lb (34 kg).


History


Pearl hunting

The ancient chronicle Mahavamsa mentions the thriving pearl industry in the port of Oruwella in the Gulf of Mannar in
Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
. It also records that eight varieties of pearls accompanied
Prince Vijaya According to the ''Mahāvaṃsa'' chronicle, Prince Vijaya (c. 543–505 BCE) was the first Sinhalese monarchy, Sinhalese king. Legends and records from both Indian and Sri Lanka sources say that he along with several hundred followers came to ...
's embassy to the Pandyan king as well as king
Devanampiya Tissa Tissa, later Devanampiya Tissa, was one of the earliest kings of Sri Lanka based at the ancient capital of Anuradhapura from 247 BC to 207 BC. His reign was notable for the arrival of Buddhism in Sri Lanka under the aegis of the Mauryan ...
's embassy to
Emperor Ashoka Ashoka (, ; also ''Asoka''; 304 – 232 BCE), popularly known as Ashoka the Great, was the third emperor of the Maurya Empire of Indian subcontinent during to 232 BCE. His empire covered a large part of the Indian subcontinent, s ...
.
Pliny the Elder Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic '' ...
(23–79AD) praised the pearl fishery of the Gulf as most productive in the world. For thousands of years, seawater pearls were retrieved by divers in the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...
in areas such as the
Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...
, the Red Sea and the
Gulf of Mannar The Gulf of Mannar ( ) is a large shallow bay forming part of the Laccadive Sea in the Indian Ocean with an average depth of .
. Evidence also suggest a
prehistoric Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...
origin to pearl diving in these regions. Starting in the
Han Dynasty The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...
(206 BC–220 AD), the
Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...
hunted extensively for seawater pearls in the
South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Phil ...
.
Tanka is a genre of classical Japanese poetry and one of the major genres of Japanese literature. Etymology Originally, in the time of the ''Man'yōshū'' (latter half of the eighth century AD), the term ''tanka'' was used to distinguish "short poem ...
pearl divers of twelfth century China attached ropes to their waists in order to be safely brought back up to the surface. When Spanish conquistadors arrived in the Western Hemisphere, they discovered that around the islands of
Cubagua Cubagua Island or Isla de Cubagua () is the smallest and least populated of the three islands constituting the Venezuelan state of Nueva Esparta, after Margarita Island and Coche Island. It is located north of the Araya Peninsula, the closest ...
and
Margarita A margarita is a cocktail consisting of Tequila, triple sec, and lime juice often served with salt on the rim of the glass. The drink is served shaken with ice (on the rocks), blended with ice (frozen margarita), or without ice (straight up). T ...
, some 200 km north of the
Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...
n coast, was an extensive pearl bed (a bed of pearl oysters). One discovered and named pearl,
La Peregrina pearl La Peregrina is one of the most famous pearls in the world. Once owned by several Spanish monarchs, its history spans almost 500 years and recently belonged to actress Elizabeth Taylor. The jewel is now in private ownership. Origin of name '' ...
, was offered to
Philip II of Spain Philip II) in Spain, while in Portugal and his Italian kingdoms he ruled as Philip I ( pt, Filipe I). (21 May 152713 September 1598), also known as Philip the Prudent ( es, Felipe el Prudente), was King of Spain from 1556, King of Portugal from ...
who intended to give it as a gift for his daughter on the occasion of her marriage, but 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 Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...
in 1560 by a
slave Slavery and enslavement are both the state and the condition of being a slave—someone forbidden to quit one's service for an enslaver, and who is treated by the enslaver as property. Slavery typically involves slaves being made to perf ...
worker who was rewarded with his liberty, and his owner with 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 Pearl hunting, also known as pearling, is the activity of recovering pearls from wild molluscs, usually oysters or mussels, in the sea or freshwater. Pearl hunting was prevalent in the Persian Gulf region and Japan for thousands of years. On the ...
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.


British Isles

Pearls were one of 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 The Abernethy pearl, also known as the Little Willie pearl, is a freshwater pearl discovered in the River Tay of Perth, Scotland in 1967. The pearl is named after its discoverer, William Abernethy (1925–2021). It was previously known as Bill's p ...
in the
River Tay The River Tay ( gd, Tatha, ; probably from the conjectured Brythonic ''Tausa'', possibly meaning 'silent one' or 'strong one' or, simply, 'flowing') is the longest river in Scotland and the seventh-longest in Great Britain. The Tay originates ...
had resulted in heavy exploitation of mussel colonies during the 1970s and 80s by weekend warriors. When it was permitted it was carried on mainly by
Scottish Travellers Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...
who found pearls varied from river to river with the
River Oykel The River Oykel ( gd, Òiceall or , ) is a major river in northern Scotland that is famous for its salmon fishing. It rises on Ben More Assynt, a few miles from Ullapool on the west coast of Scotland, and drains into the North Sea via the Kyle o ...
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.


Pearl farming

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 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 William Saville-Kent (10 July 1845 – 11 October 1908) was an English marine biologist and author. Early life Born in the town of Sidmouth in Devon, South West England on 10 July 1845, William Saville-Kent was the son of Samuel Saville Kent ( ...
who passed the information along to Tatsuhei Mise and Tokichi Nishikawa from
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
. The second category includes 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 a beaded cultured pearl is generally a polished sphere made from freshwater
mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...
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 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 was developed by the British Biologist
William Saville-Kent William Saville-Kent (10 July 1845 – 11 October 1908) was an English marine biologist and author. Early life Born in the town of Sidmouth in Devon, South West England on 10 July 1845, William Saville-Kent was the son of Samuel 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 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 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 the I.C.P. Canning Factory (International Pearl Company L.T.D.) in Nagasaki Pref. Japan.


Timeline of pearl production

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 Mise. 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 at
Kuri Bay Kuri Bay is a remote coastal bay in the far north of Western Australia in the Kimberley region, about north of Broome. It is a designated point on the Western Australian Forecast Areas, utilised by the Bureau of Meteorology as a boundary for ...
and Port Essington in Australia, and
Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...
. Japanese companies were involved in all projects using technicians from the original Mitsubishi South Sea pre-war projects. Kuri Bay is now the location of one of the largest and most well-known pearl farms owned by
Paspaley Paspaley, officially the Paspaley Pearling Company, a private company, is Australia's largest and oldest pearling company; that cultivates, farms, harvests, wholesales and retails South Sea pearls for the purposes of luxury jewellery supply a ...
, the biggest producer of South Sea pearls in the world. In 2010, China overtook Japan in akoya pearl production.Pearl Guide: comparison Japan – China akoya production
. pearl-guide.com
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 two decades, cultured pearls have been produced using larger oysters in the south
Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
and
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...
. The largest pearl oyster is the ''
Pinctada maxima ''Pinctada maxima'' is a species of pearl oyster, a marine bivalve mollusk in the family Pteriidae, the pearl oysters. There are two different color varieties: the Silver-lipped oyster and the Gold-lipped oyster. These bivalves are the largest ...
'', which is roughly the size of a dinner plate. South Sea pearls are characterized by their large size and warm luster. Sizes up to 14 mm in diameter are not uncommon. In 2013, Indonesia Pearl supplied 43 percent of South Sea Pearls international market. The other significant producers are
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
,
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
,
Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...
and
Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
.


Freshwater pearl farming

In 1914, pearl farmers began growing
cultured freshwater pearls Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Comm ...
using the pearl mussels native to
Lake Biwa is the largest freshwater lake in Japan, located entirely within Shiga Prefecture (west-central Honshu), northeast of the former capital city of Kyoto. Lake Biwa is an ancient lake, over 4 million years old. It is estimated to be the 13th ol ...
. This lake, the largest and most ancient in Japan, lies near the city of
Kyoto Kyoto (; Japanese: , ''Kyōto'' ), officially , is the capital city of Kyoto Prefecture in Japan. Located in the Kansai region on the island of Honshu, Kyoto forms a part of the Keihanshin metropolitan area along with Osaka and Kobe. , the ci ...
. 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 has caused the virtual extinction of the industry. 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 is the second-largest lake in Japan, located 60 km to the north-east of Tokyo. In a narrower sense and officially, Lake Kasumigaura refers to a waterbody with an area of 167.63 km2. In a wider sense, Lake Kasumigaura can also refer t ...
. This industry has also nearly ceased production, due to pollution. Currently, the Belpearl company based out of Kobe, Japan continues to purchase the remaining Kasumiga-ura pearls. Japanese pearl producers also invested in producing cultured pearls with
freshwater mussel Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves that live in fresh water as opposed to salt water, which is the main habitat type for bivalves. The majority of species of bivalve molluscs ...
s in the region of
Shanghai Shanghai (; , , Standard Mandarin pronunciation: ) is one of the four direct-administered municipalities of the People's Republic of China (PRC). The city is located on the southern estuary of the Yangtze River, with the Huangpu River flow ...
,
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. China has since become the world's largest producer of freshwater pearls, producing more than 1,500 metric tons per year (in addition to metric measurements,
Japanese units of measurement Traditional Japanese units of measurement or the shakkanhō (, "''shaku–kan'' system") is the traditional system of measurement used by the people of the Japanese archipelago. It is largely based on the Chinese system, which spread to Japan and ...
such as the kan and momme are sometimes encountered in the pearl industry). Led by pearl pioneer
John Latendresse John Robert Latendresse (July 26, 1925 in South Dakota – July 23, 2000) was an American collector, known for being the "father of American cultured freshwater pearls" - USGS. He left home at 13, and lying about his age, joined the U.S. Marines ...
and his wife Chessy, the United States began farming
cultured freshwater pearls Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Comm ...
in the mid-1960s. ''
National Geographic ''National Geographic'' (formerly the ''National Geographic Magazine'', sometimes branded as NAT GEO) is a popular American monthly magazine published by National Geographic Partners. Known for its photojournalism, it is one of the most widely ...
'' 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.


Momme weight

For many cultured pearl dealers and wholesalers, the preferred weight measure used for loose pearls and pearl strands is the
momme Momme may refer to: * Momme Andresen (1857–1951), German industrial research chemist * Momme Peterson (1771–1835), Danish-Norwegian businessperson and politician * A Japanese historic unit of weight: Japanese units of measurement#Momme; or uni ...
. Momme is a weight measure used by the Japanese for centuries. Today, momme weight is still the standard unit of measure used by most pearl dealers to communicate with pearl producers and wholesalers. One momme corresponds to 1/1000 kan. Reluctant to give up tradition, the Japanese government formalized the kan measure in 1891 as being exactly 3.75 kilograms or 8.28 pounds. Hence, 1 momme = 3.75 grams or 3750 milligrams. In the United States, during the 19th and 20th centuries, through trade with Japan in silk cloth the momme became a unit indicating the quality of silk cloth. Though millimeter size range is typically the first factor in determining a cultured pearl necklace's value, the momme weight of pearl necklace will allow the buyer to quickly determine if the necklace is properly proportioned. This is especially true when comparing the larger south sea and Tahitian pearl necklaces.


In jewelry

The value of the pearls in jewelry is determined by a combination of the luster, color, size, lack of surface flaw and symmetry that are appropriate for the type of pearl under consideration. Among those attributes, luster is the most important differentiator of pearl quality according to jewelers. All factors being equal, however, the larger the pearl the more valuable it is. Large, perfectly round pearls are rare and highly valued. Teardrop-shaped pearls are often used in pendants.


Gallery

File:Remontoir horloge, zgn. ‘boule de Genève’ met bijpassende chatelaine, objectnr KA 3639.jpg, A so-called "
Boule de Genève A Boule de Genève (Geneva ball) is a type of pendant watch in the shape of a small ball or sphere originating from Geneva, (Switzerland). The dial is usually at the bottom of the sphere facing the floor, at the opposite side of the jump ring on ...
" with a matching
chatelaine Chatelaine may refer to: * Chatelaine (chain), a set of short chains on a belt worn by women and men for carrying keys, thimble and/or sewing kit, etc. *Chatelaine (horse), a racehorse * ''Chatelaine'' (magazine), an English-language Canadian wom ...
covered in white pearls.
Amsterdam Museum The Amsterdam Museum, known until 2010 as the Amsterdam Historical Museum, is an Amsterdam-based museum dedicated to the city's past and present. Due to the renovation of its main location, the museum is temporarily located in the building the Amst ...
File:White pearl necklace.jpg, A necklace of white pearls File:Michiel J. van Miereveld - George Villiers, Duke of Buckingham - Google Art Project.jpg,
George Villiers, 1st Duke of Buckingham George Villiers, 1st Duke of Buckingham, 28 August 1592 – 23 August 1628), was an English courtier, statesman, and patron of the arts. He was a favourite and possibly also a lover of King James I of England. Buckingham remained at the ...
wearing white pearls File:Amélie von Leuchtenberg by Joseph Karl Stieler 1829.jpg, Empress Amélie of Brazil wearing her two-strand pearl necklaces and earrings set, 1829 File:Margherita of Savoy.jpg, Queen of Italy,
Margherita of Savoy Margherita of Savoy (''Margherita Maria Teresa Giovanna''; 20 November 1851 – 4 January 1926) was Queen of Italy by marriage to Umberto I. Life Early life Margherita was born to Prince Ferdinand of Savoy, Duke of Genoa and Princess Elisabeth ...
, owned one of the most famous collections of natural pearls. She is wearing a multi-strand choker and a rope of pearls File:Armband, av orientaliska pärlor, rosenstenar och guld, 1840-tal - Hallwylska museet - 109866.tif, Pearl bracelet from the 1840s File:Earrings 1.JPG, Pearl earrings File:"Pearl Trader" painting on mica in 1870 detail, from- Indian - Leaf from Bound Collection of 20 Miniatures Depicting Village Life - Walters 35176C (cropped).jpg, "Pearl Trader" painting on
mica Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is ...
in 1870
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...


Shapes

Pearls are generally of spherical shapes. Perfectly round pearls are the rarest and most valuable shape. Semi-rounds are also used in necklaces or in pieces where the shape of the pearl can be disguised to look like it is a perfectly round pearl. Button pearls are like a slightly flattened round pearl and can also make a necklace, but are more often used in single pendants or earrings where the back half of the pearl is covered, making it look like a larger, rounder pearl. Pear-shaped pearls sometimes look like teardrop pearls and are most often seen in earrings, pendants, or as a center pearl in a necklace. Baroque pearls have a different appeal; they are often highly irregular with unique and interesting shapes. They are also commonly seen in necklaces. Circled pearls are characterized by concentric ridges, or rings, around the body of the pearl. In general, cultured pearls are less valuable than natural pearls, whereas imitation pearls have almost no value. One way that jewelers can determine whether a pearl is cultured or natural is to have a gemlab perform an X-ray examination of the pearl. If X-rays reveals a nucleus, the pearl is likely a bead-nucleated saltwater pearl. If no nucleus is present, but irregular and small dark inner spots indicating a cavity are visible, combined with concentric rings of organic substance, the pearl is likely a cultured freshwater.
Cultured freshwater pearls Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels. These pearls are produced in Japan and the United States on a limited scale, but are now almost exclusively produced in China. The U.S. Federal Trade Comm ...
can often be confused for natural pearls which present as homogeneous pictures which continuously darken toward the surface of the pearl. Natural pearls will often show larger cavities where organic matter has dried out and decomposed.


Lengths of pearl necklaces

There is a special vocabulary used to describe the length of pearl necklaces. While most other necklaces are simply referred to by their physical measurement, pearl necklaces are named by how low they hang when worn around the neck. A ''collar'', measuring 10 to 13 inches or 25 to 33 cm in length, sits directly against the throat and does not hang down the neck at all; collars are often made up of multiple strands of pearls. ''Pearl chokers'', measuring 14 to 16 inches or 35 to 41 cm in length, nestle just at the base of the neck. A strand called a ''princess length'', measuring 17 to 19 inches or 43 to 48 cm in length, comes down to or just below the collarbone. A ''matinee length'', measuring 20 to 24 inches or 50 to 60 cm in length, falls just above the breasts. An ''opera length'', measuring 28 to 35 inches or 70 to 90 cm in length, will be long enough to reach the breastbone or sternum of the wearer; and longer still, a ''pearl rope'', measuring more than 45 inches or 115 cm in length, 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
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
during the 1950s by the GIs bringing strands of cultured akoya pearls home from
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, a 3.5
momme Momme may refer to: * Momme Andresen (1857–1951), German industrial research chemist * Momme Peterson (1771–1835), Danish-Norwegian businessperson and politician * A Japanese historic unit of weight: Japanese units of measurement#Momme; or uni ...
, 3 mm to 7 mm graduated strand was much more affordable than a uniform strand because most of the pearls were small.


Colors

Earrings and necklaces can also be classified on the grade of the color of the pearl: saltwater and freshwater pearls come in many different colors. While white, and more recently black, saltwater pearls are by far the most popular, other color tints can be found on pearls from the oceans. Pink, blue, champagne, green, and even purple saltwater pearls can be encountered, but to collect enough of these rare colors to form a complete string of the same size and same shade can take years. The vast majority of inexpensive colored pearls have been subjected to some form of dye, often a fabric dye. This dye will only tend to penetrate the first layer or two of nacre, but this is enough to impart vivid and sometimes garish color to otherwise white pearls. Truly valuable pearls are never dyed, and this process is not believed to add and in most cases would only subtract from their market value.


Religious references


Hindu scriptures

The
Hindu Hindus (; ) are people who religiously adhere to Hinduism.Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for ...
tradition describes the sacred Nine Pearls which were first documented in the
Garuda Purana The ''Garuda Purana'' is one of 18 ''Mahāpurāṇa'' texts in Hinduism. It is a part of Vaishnavism literature corpus, primarily centering around Hindu god Vishnu. Composed in Sanskrit and also available in various languages like Gujarati an ...
, one of the books of the Hindu scriptures. Ayurveda contains references to pearl powder as a stimulant of digestion and to treat mental ailments. According to Marco Polo, the kings of
Malabar Malabar may refer to the following: People * Malabars, people originating from the Malabar region of India * Malbars or Malabars, people of Tamil origin in Réunion Places * Malabar Coast, or Malabar, a region of the southwestern shoreline o ...
wore a necklace of 108 rubies and pearls which was given from one generation of kings to the next. The reason was that every king had to say 108 prayers 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 wedding ceremony. The Pearl, which can be transliterated to "Moti", a type of "Mani" from
Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...
, is also associated with many Hindu deities, the most famous being the
Kaustubha Kaustubha () is a divine ruby or ''ratnam'' (gem) in Hindu mythology. This gem is in the possession of Vishnu, granting him the epithet of ''Kaustubhadhari''. It is believed in Hindu scriptures to be the most magnificent ''ratnam'' in all of cr ...
that
Lord Vishnu Vishnu ( ; , ), also known as Narayana and Hari, is one of the principal deities of Hinduism. He is the supreme being within Vaishnavism, one of the major traditions within contemporary Hinduism. Vishnu is known as "The Preserver" within t ...
wears on his chest.


Hebrew scriptures

The Hebrew word פְּנִינִים 'pearl(s)' appears in several places in the Hebrew Bible (Job 28:18; Proverbs 3:15; 8:11; 20:15; 31:10; Lamentations 4:7), although its etymology is unclear.


New Testament scriptures

In a
Christian Christians () are people who follow or adhere to Christianity, a monotheistic Abrahamic religion based on the life and teachings of Jesus Christ. The words ''Christ'' and ''Christian'' derive from the Koine Greek title ''Christós'' (Χρι ...
New Testament The New Testament grc, Ἡ Καινὴ Διαθήκη, transl. ; la, Novum Testamentum. (NT) is the second division of the Christian biblical canon. It discusses the teachings and person of Jesus, as well as events in first-century Christ ...
parable A parable is a succinct, didactic story, in prose or verse, that illustrates one or more instructive lessons or principles. It differs from a fable in that fables employ animals, plants, inanimate objects, or forces of nature as characters, w ...
(
Matthew Matthew may refer to: * Matthew (given name) * Matthew (surname) * ''Matthew'' (ship), the replica of the ship sailed by John Cabot in 1497 * ''Matthew'' (album), a 2000 album by rapper Kool Keith * Matthew (elm cultivar), a cultivar of the Ch ...
13:45–46),
Jesus Jesus, likely from he, יֵשׁוּעַ, translit=Yēšūaʿ, label=Hebrew/Aramaic ( AD 30 or 33), also referred to as Jesus Christ or Jesus of Nazareth (among other names and titles), was a first-century Jewish preacher and religious ...
compared the
Kingdom of Heaven Kingdom of Heaven may refer to: Religious * Kingdom of Heaven (Gospel of Matthew) **Kingship and kingdom of God, or simply Kingdom of God, the phrase used in the other gospels * Kingdom of Heaven (Daviesite), a schismatic sect, founded by Will ...
to a "pearl of great price". "Again, the kingdom of heaven is like unto a merchant man, seeking goodly (fine) pearls: Who, when he had found one pearl of great price, went and sold all that he had, and bought it." The twelve gates of the New Jerusalem are reportedly each made of a single pearl in
Revelation In religion and theology, revelation is the revealing or disclosing of some form of truth or knowledge through communication with a deity or other supernatural entity or entities. Background Inspiration – such as that bestowed by God on the ...
21:21, that is, the
Pearly Gates ''Pearly gates'' is an informal name for the gateway to Heaven according to some Christian denominations. It is inspired by the description of the New Jerusalem in : "The twelve gates were twelve pearls, each gate being made from a single pearl ...
. "And the twelve gates were twelve pearls: every several gate was of one pearl: and the street of the city was pure gold, as it were transparent glass." Holy things are compared to pearls in
Matthew Matthew may refer to: * Matthew (given name) * Matthew (surname) * ''Matthew'' (ship), the replica of the ship sailed by John Cabot in 1497 * ''Matthew'' (album), a 2000 album by rapper Kool Keith * Matthew (elm cultivar), a cultivar of the Ch ...
7:6: "Give not that which is holy unto the dogs, neither cast ye your
pearls before swine A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle (mollusc), mantle) of a living animal shell, shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pea ...
, 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
Revelation In religion and theology, revelation is the revealing or disclosing of some form of truth or knowledge through communication with a deity or other supernatural entity or entities. Background Inspiration – such as that bestowed by God on the ...
18:16. "And saying, Alas, alas, that great city, that was clothed in fine linen, in purple, and scarlet, and decked with gold, and precious stones, and pearls!"


Islamic scriptures

The
Quran The Quran (, ; Standard Arabic: , Classical Arabic, Quranic Arabic: , , 'the recitation'), also romanized Qur'an or Koran, is the central religious text of Islam, believed by Muslims to be a revelation in Islam, revelation from God in Islam, ...
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, silver and pearls; and their garments there will be of silk. 52:24 Round about them will serve, evotedto them, youths andsomeas pearls well-guarded.


Additional references

The metaphor of a pearl appears in the longer
Hymn of the Pearl The Hymn of the Pearl (also Hymn of the Soul, Hymn of the Robe of Glory or Hymn of Judas Thomas the Apostle) is a passage of the apocryphal ''Acts of Thomas''. In that work, originally written in Syriac, the Apostle Thomas sings the hymn while p ...
, a poem respected for its high literary quality, and use of layered theological metaphor, found within one of the texts of
Gnosticism Gnosticism (from grc, γνωστικός, gnōstikós, , 'having knowledge') is a collection of religious ideas and systems which coalesced in the late 1st century AD among Jewish Jews ( he, יְהוּדִים, , ) or Jewish people ...
. The Pearl of Great Price is a book of scripture in
the Church of Jesus Christ of Latter-day Saints The Church of Jesus Christ of Latter-day Saints, informally known as the LDS Church or Mormon Church, is a Nontrinitarianism, nontrinitarian Christianity, Christian church that considers itself to be the Restorationism, restoration of the ...
(LDS Church) and some other
Latter Day Saint The Latter Day Saint movement (also called the LDS movement, LDS restorationist movement, or Smith–Rigdon movement) is the collection of independent church groups that trace their origins to a Christian Restorationist movement founded by Jo ...
denominations. ''
Pearl A pearl 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 carb ...
'' is a
Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English p ...
religious poem.


See also

*
Ammolite Ammolite is an opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America. It is made of the fossilized shells of ammonites, which in turn are composed primarily of aragonite, the same mineral con ...
 – another
organic gemstone This is a list of gemstones, organized by species and type. Minerals There are over 300 types of minerals that have been used as gemstones. These include: A–B *Actinolite **Nephrite () * Adamite *Aegirine *Afghanite * Agrellite *Algodonite * ...
formed primarily of fossil aragonite mollusk shells *
Bahrain Pearling Trail The Bahrain Pearling Path is a serial cultural heritage site inscribed on the UNESCO World Heritage List on June 30, 2012. It consists of three oyster beds in the northern waters of Bahrain, a segment of the coast and the seafront Bu Mahir fort i ...
, a UNESCO World Heritage Site in
Muharraq Muharraq ( ar, المحرق, al-Muḥarraq) is Bahrain's third largest city and served as its capital until 1932 when it was replaced by Manama. The population of Muharraq in 2012 was 176,583. The city is located on Muharraq Island. Bahrain Int ...
,
Bahrain Bahrain ( ; ; ar, البحرين, al-Bahrayn, locally ), officially the Kingdom of Bahrain, ' is an island country in Western Asia. It is situated on the Persian Gulf, and comprises a small archipelago made up of 50 natural islands and an ...
*
Broome, Western Australia Broome, also known as Rubibi by the Yawuru people, is a coastal pearling and tourist town in the Kimberley region of Western Australia, north of Perth. In the the population was recorded as 14,660. It is the largest town in the Kimberley reg ...
, a pearling town *
Cave pearl A cave pearl is a small, usually spherical, speleothem (cave formation) found in limestone caves. Cave pearls are formed by a concretion of calcium salts that form concentric layers around a nucleus. Exposure to moving water polishes the surface ...
*
La Pelegrina pearl La Pelegrina pearl is one of the most famous pearls in the world. Its history spans more than 350 years, and it has survived both the French Revolution of 1789–99 and the Russian Bolshevik (Communist) revolution of 1917. It was owned by Europe ...
* ''
Les pêcheurs de perles ' (''The Pearl Fishers'') is an opera in three acts by the French composer Georges Bizet, to a libretto by Eugène Cormon and Michel Carré. It was premiered on 30 September 1863 at the Théâtre Lyrique in Paris, and was given 18 performances in ...
, The Pearl Fishers'', an opera by
Georges Bizet Georges Bizet (; 25 October 18383 June 1875) was a French composer of the Romantic music, Romantic era. Best known for his operas in a career cut short by his early death, Bizet achieved few successes before his final work, ''Carmen'', whi ...
*
Oriental Pride The Oriental Pride is a natural oriental pearl. It has the shape of a drop and is white in colour. It weighs approximately 181 grains (c. 42 carats) and is one of the largest pearls ever found on earth. The size, lustre and form of the pearl distin ...
*
Pearl Maxima Pearl Maxima is one of the largest true pearls or nacreous pearls in the world. This irregularly shaped pearl has a weight of 2385 grains (119.25 grams) and is 71 millimetres long. Its colour varies from cream to gold.Naturalis (2008). Reuzenpar ...
, one of the largest nacreous pearls ever found *
Pearl of Lao Tzu The Pearl of Lao Tzu (also referred to as Pearl of Lao Tze) was once considered the largest known pearl. The pearl was found in the Palawan sea, which surrounds the island of Palawan in the Philippines, and was found by a Filipino diver. It is not ...
* Pearl of Kuwait *
Pearl of Puerto Pearl of Puerto, also referred to as Pearl of Puerto Princesa ( fil, Perlas ng Puerto) was found in the Philippine Sea by a Filipino fisherman. It measures 2.2 feet (67 cm) long, 1 foot (30 cm) wide and weighs 34 kilograms (75 lb). ...
, largest pearl in the world *
Pearl powder Pearl powder () is a preparation of crushed pearls used in China and elsewhere for skin care and in traditional Chinese medicine. Preparation Pearl powder is made from freshwater pearls or saltwater pearls below jewellery grade. These are steri ...
, used in Traditional Chinese Medicine * ''The Pearl'' (novella), a novella by
John Steinbeck John Ernst Steinbeck Jr. (; February 27, 1902 – December 20, 1968) was an American writer and the 1962 Nobel Prize in Literature winner "for his realistic and imaginative writings, combining as they do sympathetic humor and keen social ...


References


External links


The History of Pearls.
PBS Pearl History Special.
The History of Pearls.
Darpan Mangatrai. {{Authority control Bivalves and humans Gastropods and humans Gemstones Jewellery components Mollusc products Mollusc shells