Where do pearls come from

growth process

Loosely closed clam shells let in air, grains of sand, shell fragments or other small objects. When this happens, the protective reaction of the oyster, which nature has awarded it, is triggered. Around the foreign body, the process of shell formation begins. It is the growth of layers of mother-of-pearl (the mother of pearls), which is composed of aragonite, proteins and water.

The growing shell covers the sharp edges of the embedded bodies so that their corners do not damage the body of the oyster. The number of layers is in the hundreds and depends on the growth time. Pearls in the shell appear after 2-3 years, large specimens grow 7-8 years.

Proteins occupy the gaps around the aragonite crystals, due to which the shell of the pearl becomes strong. The top coat consists of only calcium carbonate, hence the pure pearlescent sheen.

Cultured pearls

Despite all the difficulties and dangers, the extraction of sea pearls has become so large-scale that some deposits began to be depleted until they were completely closed. An unexpected solution to this problem appeared in the 1990s. XIX century. There are several legends about how the Japanese oyster farm owner Mikimoto came up with the idea of ​​growing (cultivating) pearls on special plantations. His idea proved to be successful, and currently over 90% of the pearls on the world market are cultured.

It is wrong to consider cultured pearls in a shell artificial. It is as natural as pearls grown in natural conditions. Since the growth process itself also takes place in the shell of the mollusk. The only difference is this: the “seed” is placed inside the shell by a person. The process of growing a cultured pearl is quite complex and painstaking. Its duration takes from 3 to 8 years and is constantly being improved. What will be the result of the pearl in the shell and how successfully the growth will end is unknown.

The nuclear method of cultivation implies that a seed, a core, is artificially placed in a pearl oyster. Usually it is a ball 6 to 9 mm in diameter. And although everything looks quite simple in the description, the procedure itself is complex.

The first thing to do is to pick up a shellfish for seed. It should be a young pearl mussel with a well-developed gonad, a reproductive gland that produces mother-of-pearl. In addition, she must have a good robe. After the introduction of the core, the mollusk goes to a special lagoon, where it spends the time remaining until the appearance of the pearl, in favorable conditions, and is under human supervision.

Despite all this, the effectiveness of this method is not one hundred percent. The pearl oyster can throw out the seed or die. If everything goes well, a centimeter pearl can grow in a year. The advantages of this method include a high growth rate and a perfect pearl shape. But there are also significant disadvantages: the actual layer of mother-of-pearl on such a pearl is usually no more than 1 mm. Hence the ideal spherical shape. And it is quite difficult to call such pearls natural. You do not need to be a professional, just take the pearl in your hand, and it heats up quickly. In contrast, natural pearls remain cold in the hand and feel heavy.

More difficult is the nuclear-free way of growing pearls. It has become widespread in China. In this case, the seed has a tiny size. Usually this is a grain of mother-of-pearl, taken from the shell itself. This causes a long process of growth from 3 to 8 years. However, the long wait is compensated by the excellent quality that cultured pearls have in their shells. It is not inferior to the natural counterpart, often having advantages in color and size.

How pearls are formed

When a foreign body appears in the mantle area, the mother-of-pearl produced by these special cells envelops it in concentric layers and, thus, isolates it from the body of the mollusk, simultaneously creating the beginning of the future pearl. If a foreign body gets between the mantle and one of the shell valves, then the pearl, as a rule, grows together with its mother-of-pearl layer. When a grain of sand gets inside the mantle, a so-called free pearl is formed, which, as a rule, has a rounded shape.

Another prerequisite for the formation of pearls is the penetration of epithelial cells into the connective tissue of the mantle, which, by division, form a cyst (“pearl pouch”) and further, releasing mother-of-pearl, ensure the formation of a pearl of a spherical shape.

The formation of pearls occurs in the following areas of the body of mollusks:

• thickened edge of the mantle of the mollusk;
• the muscle that closes the shell valves;
• directly below the apical cavity, in the upper part of the mantle.

Why are pearls different?

The shape of a pearl is influenced by its location in the shell.
: if it grows on the body of a mollusk without contact with the shell valve, then its shape will be spherical, or almost spherical; if it is in contact with the sash, then as a result it will look like a growth.

The color and luster of the pearl depends on the thickness of the mother-of-pearl layer.
, the thickness and transparency of the underlying layer, impurities in the aragonite of which it consists, on the type of water, on the geographical location, on the state of the mollusks themselves, and it happens that on impurities in the water. The most rare, and, as a result, expensive, is the blue pearl found off the coast of Indonesia.

Having a fairly complete understanding of how pearls are formed, presenting in detail the mechanisms and patterns of this process, modern experts quite successfully grow this mineral on the territories of special "plantations" by breeding pearl oysters - this method is much more effective than traditional fishing. Plantations are shallow coastal backwaters with warm water, where shellfish feel comfortable and safe - a kind of incubator.

Not relying on the mercy of nature, "farmers" carefully open the shell and place the basis for the future pearl in it - small fragments of shells, beads and other similar items can be used for this.

In the body of the mollusk, thus, the process of isolating the foreign body is started by coating it with mother-of-pearl.

Varieties of pearls distinguished according to their origin:

• Natural sea pearl
  - the rarest and, therefore, the most expensive variety, mined in the southern seas off the coasts of Japan, Sri Lanka, in the Persian Gulf. The search for bivalve shells on the seabed, and then in them for pearls, is carried out by professional pearl divers. Finding a shell with a pearl is considered good luck, and beautiful, regular shapes with a smooth surface are quite rare prey;
• Natural river pearls
  - a cheaper variety, as it is more common, it is easier to extract, and pearls in shells are more common, sometimes several at once. Freshwater "pearl" mollusks live in the rivers of Europe, China, America. River pearls are smaller than sea pearls, often irregular in shape, less shiny.

These two varieties are also called "natural" or even "wild" pearls.

• Cultured pearls
  ("tamed") - in fact, the same marine, but its receipt is not planned and is carried out purposefully, unlike random extraction;
• Imitation pearl
  - these are beads imitating a mother-of-pearl mineral, covered with paint of the corresponding color; Material and size may vary.

The pearl grows fastest in the first year of its existence - up to 2-3 millimeters per year.In the future, the growth rate slows down significantly and is about less than half a millimeter per year.

The larger size of sea pearls compared to river pearls is explained by the more saturated biochemical composition of sea water. But on the other hand, river mollusks are much "fertile".

The formation of pearls in the shell is, in essence, a protective reaction of the mollusk organism, which develops if a foreign body enters the mantle or in the space between the mantle and the shell; an attempt to neutralize an alien particle, as if to isolate oneself from it. It is this way of coping with minor annoyances that has made shell-dwelling molluscs a prey to humans.

The process of pearl formation

The process of formation of pearls in the shells of marine and freshwater mollusks was discovered by people a very long time ago. It was once believed that pearls are the tears of mermaids or orphans, which were collected by angels and hidden in shells. And only with the development of science was it established how pearls appear in a shell.

It is formed as a result of a protective reaction of a mollusk to a foreign body that has got inside the shell, most often a grain of sand or a small pebble acts as the basis for a pearl stone. The mollusk cannot push the foreign object out, therefore, it begins the process of enveloping it with epithelial cells in order to reduce the irritating effect on the delicate body.

As a result of the increased "work" of the mollusk, the foreign body is covered with several layers of mother-of-pearl - this substance lines the inner sides of the shell valves. Sometimes the basis for a pearl is a small parasite, a gas bubble, or a dead piece of mollusk tissue; the shape and beauty of the pearl depends on the location of the foreign object.

The sequence of the process of pearl formation, or how pearls appear in the shell:

• The ingress of a foreign body into the shell.
• Enveloping a foreign object with an outer film.
• The formation of a pearl sac.
• Layering of mother-of-pearl.

If the pearl bag is formed close to the shell valve, an irregularly shaped pearl is formed, while one of its sides fuses with the surface of the shell and does not have a mother-of-pearl coating. When the pearl sac is located in the muscles of the mollusk, due to the constant contraction of the tissues, the pearl also acquires an irregular, sometimes bizarre shape.

When a sac is formed deep in the mantle of a mollusk, it grows perfectly round, evenly covered with mother-of-pearl.

Mollusks that are able to grow high-quality pearls are called pearl mussels, they can be related to freshwater and marine mollusks. Theoretically, any shellfish can produce pearls, but in jewelry, only pearl stone obtained from several representatives of reservoirs is valued. These include:

• European river pearl;
• Kamchatka;
• Dahurian;
• barley;
• toothless;
• folded comb;
• giant tridacna;
• noble pinna;
• giant strombus;
• mussels.

WHAT COLORS ARE PEARLS IN NATURE

The color spectrum of pearls includes 120 different shades. The colors of pearls are taken into account in its evaluation along with the shape and size.

The best natural pearls are colorless and look white. Due to its translucency, it has a soft silvery sheen and shimmers with rainbow colors in the light.

Earrings made of natural white pearls 8 mm, 500 USD

The value of multi-colored pearls is determined depending on the purity and rarity of the color.

The most expensive pearls are blue, lilac, pink, gold and black of good saturation.

Natural pink and orange pearls from 3.3 mm to 13 mm

What determines the color of pearls

The appearance of white and colored pearls is determined by the following factors:

• type of mollusk;
• the degree of transparency of the mother-of-pearl layer - the more transparent it is, the lighter the pearl;
• color of the organic layer under mother of pearl;
• concentration of pearl aragonite and conchiolin in the shell - aragonite is colorless or white, and conchiolin has shades from to black;
• saturation and composition of impurities of chemical elements in water.

Jewelry classification system

The jewelry industry uses the following gradation of pearls:

Quality	Shine	Defects	Selection of beads in the product	Configuration	Mother-of-pearl thickness
AAA	great	95-99% absent	excellent	spherical	thick
AA+	great	90-95% are absent	excellent	spherical	thick
AA	very good	80-90% are absent	very good	spherical	medium to thick
A	good	minor	good	close to spherical	average
B, C	Pearls with surface defects or low luster are practically not used in the jewelry industry. The exceptions are valuable types of baroque and semi-baroque.

Gold and white

Stones with a muted sheen are called golden and are mined on the coasts of Indonesia and Australia. Sizes are up to 1 cm. The center where black pearls are concentrated is Tahiti. This extraordinary jewel is worthy of kings. The sizes are larger (1.5-1.8 cm), the shades are blue, purple, green.

White pearls up to 2 cm in diameter appear from silver-lipped mollusks. These creatures are capricious, so each copy that is obtained from them is considered exclusive. The Philippines and Australia specialize in growing.

Since the pearl is formed naturally during cultivation, the resulting specimens cannot be called artificial. However, imitations have already existed since the 15th century. These are the famous Roman balls. Hollow inside, they were made of ordinary glass and filled with paraffin. The mother-of-pearl essence from fish scales has also spread to cover the surfaces of fakes.

Characteristics of the jewels

A standard pearl is white, but depending on the type of mollusk and its habitat, it can be pink, orange-yellow, blue, dark brown or black-violet. The color and shape of a pearl stone affect its price; blue pearls are considered the rarest and most expensive.

Several such pebbles can grow in one shell, up to several tens of pearls are found in large mollusks, with an increase in their number, the size of the formations decreases.

According to the habitat of mollusks, two types of pearls are distinguished:

1. Freshwater (river) is an inexpensive product, it has long been used to make jewelry, and jewelry made from river pearl stone was available even to peasant women. Feature of freshwater pearls - irregular shape, slightly matte luster, waviness, high strength.
2. Marine - this type of pearl is highly valued, as it is mined by hand off the coast of the Persian Gulf, near Sri Lanka. Divers dive to a depth of several tens of meters and catch hundreds of shells, looking for among them those with a pearl inside. The profession of a diver is very dangerous, as a person dives into the water without any equipment, taking only a knife with him. During diving, the body experiences severe overloads, often during a dive a person is attacked by sharks.

The amount of pearl stone formed in nature is too small and cannot satisfy the needs of jewelers and jewelry lovers. The extraction of natural pearls is harmful to the environment, since when shellfish are caught, many shells are destroyed that do not contain precious inclusions. Of the ten shells, only one contains a quality pearl, the remaining nine are opened and thrown away.

When it was established how pearls are formed in the shell, a new direction appeared - the cultivation of pearls.

Features of the formation of pearls

Many mollusks have the ability to form pearls, but the Pinctada sea mollusks are the main supplier of jewelry. Under natural conditions, the mother-of-pearl layer is formed in a period of up to 7 years, during which thousands of the thinnest films are slowly deposited. The shape and size of the pearl depends on where the initial irritant (nucleus) is fixed. When it is located inside the tissue of the clam's mantle, you can expect the appearance of a bubble pearl of a round shape. If the location of the nucleus shifts to the inner surface of the valve, then a blister-pearl grows, attaching to the wall of the shell.

As a result of the peculiarities of formation, bubble formations, being in soft tissues, fully mature and form an optimal spherical shape, and when cut, a blister-pearl has an attachment site to the leaf, on which the mother-of-pearl layer is not fully formed. This circumstance leads to the incompleteness of the shape of the gem - a hemispherical or partially spherical variety. A defect, of course, reduces the value of the stone and leads to the need to mask the defective area in the manufacture of jewelry.

Types of pearl fishing in the world

• more widely distributed;
• much easier to get;
• greatly inferior in brilliance and form.

River pearls also have their advantages over sea ones. It is more durable and wear-resistant, wears out less over time. For the extraction of freshwater pearls, an underwater mask or a specially adapted tube is enough. The latter was used in ancient times and now, rather, it will look like an outlandish device. Basically, a shell with pearls is located at the bottom of freshwater rivers and lakes and is not found there alone, but in whole colonies. All this greatly simplifies the collection of freshwater pearls, which is often not difficult even for an amateur.

In contrast, sea pearls are mined by professionals.
Firstly, the sea shell with pearls lies deep, you have to dive to a depth of 15-20 meters. Secondly, you have to dive several dozen times a day, each time remaining at a depth of more than a minute.

All this requires special skills and training. Moreover, divers for pearls in the sea are exposed to another danger, namely a possible encounter with a shark.

Nowadays, special farms are used to collect both sea and freshwater pearls. China is famous for its "pearl farms". In this country, not only fresh waters of rivers and lakes are used to grow pearls. Former rice fields, which are flooded with water and have a comfortable microclimate for shellfish, are very popular. Under such conditions, pearl mussels multiply rapidly and produce high-quality pearls. Man can only control the living conditions of mollusks, such as the composition of water, its temperature and acidity factor. The pearl's growth process requires the clams to be turned over at times. This will give the shape of the pearl more symmetry.

Cultured sea and river pearls what is it, criteria and prices

Cultured pearls, like natural pearls, are formed naturally inside shellfish. The only difference is who initiates the formation of the pearl. In the case of natural pearls, the cause of the appearance of the pearl is a random natural factor, while in the case of cultured pearls, a person places the seed for the growth of the pearl inside the mollusk. Even knowing what it is - cultured pearls, it is almost impossible to distinguish it from natural without special expertise.

Natural and cultured pearls are judged according to the same criteria. Russia does not have its own system for evaluating pearls. In the rest of the world, pearls are graded using a system developed by the Gemological Institute of America (GIA).

According to the GIA system, the quality of pearls is evaluated according to 6 or 7 parameters, depending on what the piece of jewelry is. If the jewelry is a ring, earrings, bracelet or pendant with one or more pearls, the quality of the pearl is evaluated according to 6 criteria. In the case of a necklace or string of pearls, a seventh evaluation parameter appears, which is called "matching". It only applies to necklaces or "shipping strings" of pearls where multiple pearls are drilled through and put on a string.

Below are all the evaluation criteria:

• Size (English Size);
• Shape (English Shape);
• Color (English Color);
• Glitter (eng. Luster);
• Surface quality (English Surface);
• Mother-of-pearl quality (English Nacre Quality);
• Matching - only for necklaces or no pearls.

There are four types of cultured pearls available on the jewelry market. Three of them are grown in salty sea water and one in fresh water.

• "Akoya" (marine);
• "Pearl of the South Seas" (marine);
• "Black Tahitian" (marine);
• "Freshwater Chinese" (another name for "Chinese nuclear-free").

Akoya pearl.
The Japanese king of cultured pearls, Kokichi Mikimoto, invented a method for growing cultured pearls. The name "akoya" comes from the Japanese word "akoya-kai". So in Japan they call bivalve mollusks in which this type of pearl grows.

This is one of the most round types of cultured sea pearls. Its main properties: small size of pearls, perfectly round shape, bright brilliance and high clarity of reflection. Up to 80% of akoya are round or nearly round. In Japan, there is a special name for a perfectly round akoya - "hanadama", which in Japanese means "flower pearl" or "round flower". Hanadama is the highest grade of pearl roundness.

Pearls of the South Seas.
This type of pearl is grown closer to the equator - in warm waters off the coast of Australia, Indonesia, the Philippines and Myanmar. The clam that creates this type of pearl is called Pinctada Maxima, and its shells are simply huge. In nature, mollusks grow up to 30 cm in diameter.

The pearls obtained with the Pinctada maxima are the largest and one of the most expensive in the world. Small pearls are considered to be 8-10 mm in diameter, while large ones reach 20-22 mm in diameter. The average size of a South Sea pearl is 13 mm. With a diameter of 8 to 13 mm, the price per thread is not very high, but if the diameter of the pearls in the thread exceeds 13 mm, then the amount for this piece of jewelry increases significantly. A string of pearls with a diameter of 13-14 mm usually costs twice as much as a string of similar quality, but from pearls of 10-12.5 mm.

Round and almost round pearls are relatively rare, usually no more than 18-20% of the total mined volume.

Black Tahitian pearls.
This type of sea pearls follows the high cost of pearls of the South Seas. It appeared on the jewelry market relatively recently, in the early 1970s. Until that time, no one suspected its existence. The special type of mollusk in which these unusual pearls grow is called Pinctada Margaritifera Cumingii.

Tahitian pearls are the only ones of all types that have a natural black color. All other types of pearls become black only as a result of artificial dyeing.

The range of colors of black Tahitian pearls is quite wide: all shades of gray, black and brown with tints of pink, purple, green and blue.

Prices for individual black Tahitian pearls of the highest quality in Peacock or Eggplant colors range from $400 to $900, depending on the size.

Production

Synthetic pearls are a product that is made by human hands. Such pearls have been in demand among the fair sex for several decades. The reason is that jewelry of this type is diverse and affordable.

There are two types of artificial pearls in the world that are in the greatest demand:

1. Shell pearl.
2. majorica.

1) In the 15th-16th centuries, a technology was developed by which beads were coated with mother-of-pearl varnish. The technology has survived to this day. Any fashionista will be satisfied with the quality of such raw materials, besides, the Chanel jewelry house is steadily using this product.

In the process of work, a core is used, which is cut out from the shell of a mollusk. To prepare the coating, natural mother-of-pearl is taken, which is ground to a powder state and mixed with a special solution. The result is a large pearl with a size of 10 mm or more, which shines and shimmers. It is smooth to the touch, unlike natural, which has a porous structure.

2) In second place are Majorica pearls, they are produced in Italy. Many believe that technology has made industrial production perfect. The process is simple: several layers of mother-of-pearl are applied to an alabaster ball.

The technology was perfected on Spanish soil, on the territory of the island of Mallorca. The founder of the production of synthetic pearls was an emigrant from Germany, Eduard Hugo Hosch. His dream was two hundred production to perfection. It took no less than 120 years.

Today it is safe to say that technology and craftsmanship have helped to create pearls that are indistinguishable from natural ones, only a little in size and smoothness.

Main advantages:

1. Large size.
2. Low cost.
3. Rich palette of shades.

It is noteworthy that under artificial lighting, synthetic pearls play with brilliance and amaze with a bizarre shade.

Today, it is difficult to buy a wild pearl as an ornament, because among all the jewelry with pearls, only 2% are natural. Everything else is to some extent created by human hands. Cultured pearls are not much different from natural ones, since they are created by a person with the participation of a mollusk as well. Even an experienced jeweler can hardly distinguish between natural and cultured pearls, since visually they can be called identical.

Gem properties

Pearls do not have the strength and hardness of crystalline gemstones, but have sufficient resistance to the chemical components of air and human waste, it has a unique color palette and the ability to provide a color overflow effect. Pearls differ in their shape. The most common is the round spherical variety, but there are drop-shaped, pear-shaped, oval, in the form of a bunch or irregular shape. The closer the copy is to the shape of a ball, the more popular and more expensive it is.

Important properties of natural stone are its color, brilliance and play of light (surface interference). More than 120 varieties of pearls are distinguished by color palette. The most common color is silvery white, cream, yellow and pink shades are quite common; sometimes it is possible to get green, black and blue pearls. The color depends on the composition of the water, temperature conditions, depth, i.e. from the location of the mollusk. So, for pearls mined in Indian waters, a pale pink hue is characteristic; in Ceylon waters - yellow; near Panama - golden and brown; in the Gulf of Mexico, black and reddish brown; near the Japanese coast - white and greenish mother-of-pearl, etc.

Modern pearls are divided into natural and cultured. In turn, a natural gem can be of marine or river (freshwater) origin. The cultivated variety is obtained by artificially introducing a pearl embryo into the shell, but with further cultivation in natural conditions or conditions close to marine ones, on special farms.Imitation of pearls is also noted, but this is already a completely artificial gem.