Pearls are a gem of organic origin. It forms in the shells of both freshwater and marine molluscs. However, not all types form gem-quality pearls.
1. Pearls are the only gemstone of gem value that is extracted from living organisms. Therefore, each pearl is unique, no two identical pieces exist.
2. A pearl takes an average of five years to form. The terms of "ripening" depend on the age of the mollusk, the state of the water.
3. The process of pearl formation inside the shell of molluscs is a response to irritation caused by the presence of foreign bodies: as a rule, small parasites or grains of sand. A pearl begins to form around them. First, the shell secretes a solid - mother of pearl. It consists of the mineral aragonite (calcium carbonate) and the elastic biopolymer canchiolin.
4. The pearl has a smooth surface only on the outside. Inside, it consists of concentric layers around the core.
5. The mass of pearls is measured in grains, which is equal to 64.8 mg or 0.32 carats. Until recently, the largest specimen was considered the "Pearl of Allah" weighing 6, 35 kg. However, in recent years, information has appeared about a find weighing 34 kg. Large specimens are called "baroque" pearls, and small ones up to 25 mg - "seed".
6. In order to push the mollusk to form a gem, sometimes a foreign body is specially introduced into the shell. The result of this process will be the so-called cultured pearls (not to be confused with artificial ones). It will "grow" if a small pearl ball is placed in the shell, which will act as a nucleus. And a pearl will subsequently form around it, which has a specific spherical shape.
7. Pearls in the shape of a perfect ball or droplet are usually highly prized. The most beautiful specimens have a characteristic iridescent sheen that sparkles on the surface. This effect is called irrigation. It is caused by light passing through microcrystals of calcium carbonate. Because of this, the color of any pearl is partially determined by its surroundings.
8. Many sea pearls are found in the waters of the Red Sea, the Persian and Mexican Gulfs, as well as along the coast of Venezuela, around the Great Barrier Reef off the coast of Queensland, Australia, in Polynesia. Freshwater specimens can be found in rivers in Australia, France, China, Germany, Ireland, Scotland, and Japan. There are also many of them in Russian rivers that flow in the Arkhangelsk and Murmansk regions, in the Far East.
9. Natural pearls contain a lot of water. So that it does not lose its appearance, it should be provided with sufficient moisture. For example, periodically wipe with a damp cloth. Also, you cannot store this gem in a too dry place. Otherwise, the surface of the pearls will quickly become covered with microcracks.
