Who gives birth to pearls?

Based on their origin, sea and river pearls are distinguished. Currently, all freshwater pearls are cultured, that is, grown on a pearl farm, since commercial fishing has been banned since the 50s of the last century in almost all countries. Find out what freshwater pearls look like, what color they are and how they are formed in our article.

Freshwater pearls – what are they?

Freshwater freshwater pearls are a mineraloid, a hard gemstone extracted from the shells of river bivalve mollusks. It is not a mineral, but is valued as a gemstone along with diamonds, rubies, sapphires and emeralds. Although it was grown by humans, it is still natural and does not look different from the wild (natural). Pearls simultaneously consist of mineral (calcium carbonate) and organic (conchiolin) substances. Comes in different sizes, colors and shapes.

Saltwater and freshwater pearls: differences

Saltwater pearls are born in pearl-bearing mollusks, whose habitat is the seas and oceans. Fresh water pearls are found in pearl mussels that live in the waters of rivers and lakes. Sea mollusks, with rare exceptions (Akoya), are capable of producing one pearl. The river pearl mussel is more productive – it can contain up to 30 seeds or more. Interestingly, the thickness of the mother-of-pearl is one of the factors affecting the cost. The paradox is that freshwater pearls have a thicker nacre layer than sea pearls, and yet the former is cheaper. The thickness of the mother of pearl also affects the safety of the bead. There are also differences in shape: sea cultured pearls often have a regular spherical shape, while river pearls take on a variety of bizarre shapes. Only specialists from a gemological laboratory can reliably determine the origin of pearls by performing X-ray examinations.

How it is formed: cultivation technology

The process of pearl formation is identical for river and sea mollusks: in response to a foreign body getting inside, the mollusk turns on protection, which consists of enveloping the implant with nacre. This process takes from several months to several years. Freshwater pearls are grown using the non-nucleating method, that is, they do not have a nucleus, which is clearly visible on x-rays. To initiate the process of pearl formation, a piece of the mantle of another mollusk is manually implanted into the mantle of a freshwater mollusk. The oyster is then returned to the river. In what shells are freshwater pearls born? Not all freshwater mollusks are suitable for this, but mainly bivalves: Margaritifera, Dahurinaia laevis, Dahurinaia dahurica, etc.

Shapes, size and colors

As mentioned above, natural freshwater pearls are mostly baroque in shape, that is, irregular, but the shape of some cultivated samples is close to spherical. This feature is due to the fact that river pearl mussels are often “multiparous” and the beads interfere with each other’s growth. The shape largely depends on the location of the embryo in the mollusk. Freshwater pearls come in a wide range of colors, which is determined by the color of the shell itself. White, milky, pink, lavender – these are the main colors of freshwater pearls. The size of the beads ranges from 1 to 11 mm on average.

Where is mined

Just a century and a half ago, fishing was well developed in Russia. There were entire generations of pearl divers who caught shells that were found in rivers at shallow depths – up to 2 meters. In the 1860s, the volume of exports amounted to hundreds of thousands of royal rubles; today the fishery has been discontinued. Many people are interested in whether natural river pearls still exist. It happens, but its extraction is prohibited. Thus, the European pearl mussel has been preserved in the rivers of the Arkhangelsk and Murmansk regions, as well as Karelia, but now the mollusk, listed in the Red Books, is only an object of research. The main manufacturer is China. Freshwater pearls are also grown in Germany and North America.

Russian freshwater pearls

The pearl industry in our country deserves special attention. Russian freshwater pearls were once so highly prized that they were supplied to the royal court and exported. The production volumes amounted to tons, and 500 times more pearl mussels were caught, which was one of the reasons for the ban on fishing at the beginning of the XNUMXth century. In Peter’s times, merchants used pearls, which were mined in clean and cold northern rivers, as the equivalent of currency, making savings in them and making payments. Wealthy people were literally dressed in pearls from head to toe, as hats, clothes, and shoes were abundantly decorated with them. This was the first indicator of the family’s well-being. But peasant girls also wore pearl headdresses and jewelry, at least at their weddings. Today, kokoshniks and other elements of northern costume can be seen in ethnographic museums. On June 8, 1721, Peter I introduced a state monopoly on production, which lasted until 1736. From that moment on, the supply of pearls in the form of jewelry and placers in merchant families increased significantly. This jewel was loved both in the upper echelons of St. Petersburg society and in the royal family. The most valuable pearls were called sloping pearls; they had to be white or silver and have a close to spherical shape. Several Moscow jewelry firms traded exclusively in products made from Russian pearls until the end of the 19th century.

Where is used

Both sea and river pearls are used primarily in various jewelry, encrusted in necklaces, earrings, rings, bracelets, pendants, brooches and set in gold and silver. However, unlike any stones, it is usually not cut. The good news for pearl fans is that jewelry made from river pearl is affordable. The shape of the pearl tells the jeweler-designer what can be made from it. The process of creating a string of pearls, for example, can take years to select beads that are similar in color, shape and size. This biogenic material is also used to create hair accessories and decorative chains for glasses. Low quality pearls are used in the form of extract and powder for the production of cosmetics. The mineraloid has also found a place in the creation of accessories, decorative items, clothing and footwear design for luxury brands.

How to care for and store freshwater river pearls

Usually they try to protect jewelry and therefore wear it only for important events. The main rule in relation to both river and sea pearls is to wear jewelry with them as often as possible, because they show their best properties only in contact with the human body. Pearls in general are not afraid of the effects of cosmetics and soap, but it is important to put on jewelry at least 10 minutes after applying cosmetics and perfume. But direct sunlight and heat are destructive to beads. Periodic baths with fresh water will help maintain the shine of freshwater pearls as bright. After such bathing, dry it with a soft cloth, and the pearl thread in a horizontal position so that the base does not stretch. As for storage, it is recommended to allocate a separate box with soft upholstery for pearl jewelry, otherwise the mother-of-pearl layer may wear out from contact with the stones. Birth of pearls – this is a protective reaction of a mollusk to the introduction of a foreign object (piece of shell, organic matter) into it; to combat the foreign object, the mollusk begins to produce a special substance – mother of pearl, which consists of aragonite and calcite. Layer by layer it envelops the foreign substance, this is how the pearl grows over the years, this is how pearls are formed. Pearl is the only stone that gives birth to a living creature – a mollusk. Pearl-bearing mollusks are common in both marine and fresh waters. The best and most expensive pearls are produced by sea mollusks. These primarily include bivalves of the genus Pinctada (they form large colonies in warm seas, their life expectancy is from 3 to 11 years.)
Pinctada vulgaris – found off the coast of the Red Sea, the Persian Gulf, Sri Lanka, the island of New Guinea, and the Malacca Peninsula. The mass of pearls does not exceed 12 grains (1 grain weighs about 0,25 carats). pinctada maxima Pinctada maxima – northern and western coasts of Australia and the Malacca Peninsula. The largest mollusks. Their shell reaches 30 cm in diameter and weighs 10 kg. They give large pearls. Pinctada martensii – southern coast of Japan pinctada margaritifera pinctada margaritifera – shallow waters of the Pacific and Indian oceans off the coast of New Guinea, Australia, New Caledonia. The shells of these mollusks are most valued, but sometimes they also contain pearls, including black ones. Pinctada radiata Pinctada radiata – the coast of Central and South America. tridacna gigas The largest and largest pearls give tridacna gigas (the size of the pearls is impressive, but they have no jewelry value). The mass of the mollusks reaches 200 kg, the size of the shell is up to 1,4 m, and the weight of the pearls is up to 7 kg. Life expectancy often exceeds 100 years. Pinna nobilis Pinna nobilis – Mediterranean Sea, Pacific and Atlantic Ocean. These mollusks produce reddish, dark brown, black-purple and black pearls. Pinctada mazatlanica Pinctada mazatlanica – is a type of tropical marine bivalve mollusc. Habitat: Pacific coast of Central America, Mexico and Panama. haliotis Haliotis (lat.) — shellfish known as “abalone” (51 species). In English literature, haliotis is called abalone. This gastropod is larger than the shell itself (the shell is univalve). The shell is distinguished by its richness of color – almost the entire spectrum of shades of mother-of-pearl from white to black (pink, green, purple, etc.) Scientific name: Haliotis rufescens
Photographer: Kevin Lee “With the help of a muscular leg, Haliotis firmly presses its shell to the surface of the stone, thereby saving itself from predators and the energy of the waves, and can even stay on the stone during low tide.” http://www.jewellery.org.ua/stones/katalog-haliotis.htm Pteria Sterna Pteria Sterna – one of the types of marine bivalve mollusks. These oysters can be found in shallow waters along the tropical and subtropical Pacific coasts of the Americas, Mexico and northern Peru. Fragments of mother-of-pearl jewelry have been found in ancient burials in Mexico. The mollusk produces grey, pink, gold, green and purple pearls. Strombus gigas (lat. Lobatus gigas) – the same mollusks that give birth to the most valuable and rare pearls, conch pearls Strombus gigas – lives in the western part of the Atlantic Ocean: the Caribbean Sea, Colombia, Venezuela. Shell sizes range from 15 to 35 cm, the mollusk is found at depths from 0,3 to 35 meters, prefers sandy soil, algae and sea grasses. It feeds on seaweed. Life expectancy is about 7 years. The shell is beautiful, but also strong and durable, which is why the indigenous people of the Caribbean used it to create a variety of tools. Queen Conch (Strombus gigas) Very rarely, a pearl is found in approximately 1 in 10 shells. Strombus gigas mollusks are not capable of secreting nacre, so their pearls do not have an iridescent sheen. Pearls come in different colors, but the most expensive ones are pink (conch pearls). The shell is used for the production of cameos, and the shell itself serves as a wonderful decorative element. Sea snail Melo melo Large sea snails Melo melo live in the waters of Southeast Asia (from Myanmar to the Philippines), feeding on smaller snails. They live on the ocean floor at a depth of 30 to 100 meters. The length of the snail is from 15 to 35 centimeters. They are still used as a delicacy in Southeast Asian countries such as Vietnam and China. Vietnam was at one time the main supplier of these snails to China and a supplier of melo melo pearls (this Sea snail shell Melo melo pearls were also called Vietnamese orange pearls, because in the past small pearls were often found in snails). The mechanism by which pearls appear in snails is unknown and melo melo pearls cannot be cultured. Pearls are not mother-of-pearl, but rather porcelain, but very valuable. Nautilus Nautilus (translated from Latin as “ship”) is a genus of modern cephalopods. They have existed for millions of years, they are classified as “living fossils”, it seems that they were still contemporaries of dinosaurs. They live exclusively in seas and oceans. They do not create pearls, although the entire inside of the shell consists of mother-of-pearl, but it is this mother-of-pearl that makes them valuable. The mollusk is a spirally twisted shell, 15-23 cm in diameter, although ancient mollusks were up to 3,5 meters in size. The external color of the shell is usually brindle, and they also have amazing regeneration.
Nautilus lives in the tropical waters of the western Pacific and eastern Indian oceans and does not tolerate fresh water. It feeds on small crabs, fish and organic debris. Mercenaria mercenaria Mercenaria mercenaria – an edible bivalve mollusk. Distributed on the Atlantic coast of North America. “Non-pearl” pearls are born in the shells of this mollusk quahog . Freshwater pearl-bearing bivalves belong to the genus Unio. The most famous types: Group of live Margaritana margaritifera in a river bed in Sweden Margaritana margaritifera — Russia (Karelia, Pskov, Novgorod, Arkhangelsk regions, Kola Peninsula), Baltic states, Finland, Sweden, Norway, Great Britain, Ireland, North America.
Margaritana dahurica – Amur River basin.
Margaritana middendorffi – found in Kamchatka.
Margaritana sachalinensis — in the reservoirs of Sakhalin. Margaritana lives in the cool, clean running waters of rivers and streams, their bottom is composed of granites and crystalline schists, the depth of mollusk habitat is generally 0,4-1 meter, sometimes up to 2,4 meters. The lifespan of a margaritan is 40-50 years (sometimes up to 80 years). The active lifestyle of mollusks is 7-9 months (warm months of the year); in winter they fall into suspended animation.
Harvesting freshwater pearls involves collecting shellfish from the river bottom with your hands, toes, split poles, tongs, and pitchforks. Currently, nets are used, and in case of large accumulations, dredges are used.
Freshwater pearls also have different colors (from white to gray and greenish). The color of pearls (sea or freshwater) is probably influenced by the chemical composition of the water. Mollusk Hyriopsis cumingii Family – Unionidae (unionids are a family of freshwater mollusks), species – Hyriopsis cumingii. Found in freshwater rivers and lakes of China and Vietnam. It is the most important freshwater mollusk for Chinese pearl culture. Firstly, thanks to it, Edison pearls are born, and secondly, they are used as food for both people and as feed for domestic animals (chickens, livestock). The clam shell is used in traditional Chinese medicine and crafts. The entry was published on February 20.02.2017, XNUMX by admin in the category Pearls with tags mollusks.