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River Pearls: Formation and Care

River Pearls Formation and Care

River Pearls: Formation and Care

In the world of jewelry and costume jewellery, in most cases, it is very common to call any washbasin used to decorate and complement necklaces pearls, but in reality, pearls are washbasins made from oysters and other mollusks, and some synthetic imitations of man-made pearls.


Pearls are the oldest known gems to date and are also the only ones of organic origin, coming from calcium carbonate combined with organic substances produced by molluscs. They form inside marine or river mollusks when they detect a foreign compound inside them. The mollusk will react to such an intrusion (microorganism, food remains, grain of sand, etc.) and will try to cover or capture the invader with the same mother-of-pearl as its shell. This process occurs naturally but can also be man-made, a process now known as pearl culture.


River pearls are produced naturally, but they can also be “cultivated” by man. These are not so “persecuted” as they are not the ones that are commonly commercialized but they can easily come to our hands.

River pearls: Formation of river pearls

Next we will talk a little bit about the pearls of river cultivated by man. These pearls are cultivated in bays, lakes and rivers and in different types of freshwater mussels. The cultivation procedure consists of introducing a nucleus into the mussel and waiting until it is covered with its nacre or mother pearl until it forms the pearl itself.

In this case the nucleus introduced is nothing more than a soft tissue extracted from another mollusk that decomposes when the pearl is formed.  Approximately 10 cores can be placed at a time. In addition, if the procedure is carried out with great care, the mollusc will survive after it has been opened and it is possible to grow it again.

Cultivating on mussels is much easier and faster than on oysters, therefore the price of pearls cultivated in this way is much lower. However, one disadvantage is that the shine of these pearls is less than that of oyster cultured pearls (salt water), and it is much more difficult to achieve spherical pearls. But you get a wide range of colors in natural shades ranging from white to pink through beige and ivory.

They can also be artificially dyed by placing a dye inside the mussel that is slowly released as the pearl forms.

Another thing you can do is to paint after removing them already formed but they would only have color on the outside surface.

River pearls can be white, pink or purple. Black pearls can be obtained by dyeing the core at the time of cultivation.




Natural River Pearls

Let’s talk a bit about the quality of natural river pearls. For a person not familiar with cultured river pearls, two pearls of the same color and almost the same size are practically the same, but for an expert in the field they can be very different in quality and price. Let’s see what are the determining factors that influence the quality of these precious gems:


  • The bigger it is, the higher the price. And it will depend on the type of mollusk in which it was grown, as well as the nucleus used for its cultivation.
  • The brighter it is, the higher the price.
  • The rounder or spherical it is, the higher the price of the pearl. Those shaped like rice grains are cheaper than those shaped like potatoes, and these in turn are cheaper than those that are completely spherical. Its shape depends mainly on the type of mollusc, the core used and the growing time.
  • Depending on their color they can be cheaper or more expensive, the most demanded colors are the most expensive.
  • The thickness of the mother-of-pearl layer that is directly related to the shine and size of the pearl. The longer the nucleus spends inside the mollusk, the greater the nacre layer and therefore the higher the price. Some pearls are extracted prematurely, making the culture cheaper but with the disadvantage that the nacre layer is very weak and the pearl loses value.








Care of the river pearls

  • For being organic gems, river pearls are usually more delicate than other pieces of jewelry. Friction or contact with certain agents and chemicals can damage them.
  • If we are going to use any jewel that is composed of pearls of cultivated river, we must have the precaution and the care of placing first the cologne or cream that we normally use and then if the jewel, this not to apply any of these products on them and to avoid the risk of damaging them.
  • They must be stored in an insulated way so that they do not come into contact with harder parts, such as metals, precious stones or crystals and thus prevent their surface from being scratched and losing its shine and quality.
  • In the case of river pearl necklaces, they must be knotted separately between beads to prevent them from falling out if the thread breaks. If you use them too often, it is advisable to take the precaution of redirecting them from time to time to prevent the thread from breaking easily.
  • From time to time, jewelry made with river pearls can be washed with a delicate soap and dried with a soft cloth that does not release lint or scratch the surface of the pearl, in order to remove traces of sweat, creams, colonies, etc..
  • When making a jewelry garment with pearls we must take into account that these should not rub against any element.