One of the precious stones is the pearl, which is extracted from the shells of some mollusks that excrete mother of pearl. The word mother-of-pearl takes its origin from it. Perlmutter is the "mother of pearls". Due to the ingress of foreign matter (grains of sand, etc.) into the shell of the mollusc, pearls form. Around the object, the beginning of the deposits of pearlescent layers begins. Pearls are not only mined, but also grown on an industrial scale (mainly in Japan). For the cultivation of artificial pearls, beads from pressed shells are placed inside mollusks, then the mollusks return to the water. Ready pearl beads are extracted from the shell after a certain time. Since the extraction of natural pearls has been discontinued since 1952, in most cases today one has to deal with cultured pearls or synthetic ones. How to distinguish real pearls from fake ones?
You can evaluate real pearls by the following criteria:
The size:
it depends on the type of shellfish. The larger the size, the more expensive its price. The largest pearl weighing 6 kg, a length of 24 cm and a width of 14 cm - known as the pearl of Allah (or - the pearl of Lao Tzu).
The form:
natural pearls have different shapes. The ideal form is spherical. It can also be pearls and shapeless, which is called "baroque".
Shine:
depends on the time of the year. The winter pearl has thin layers of mother-of-pearl, the summer pearl is thickest with less glitter. To evaluate pearls, shine is very important: the stronger the shine, the more valuable the pearl.
Colour:
usually white, sometimes there is pink and cream, also yellow, green and blue. Blue pearls are the most expensive and rare.
In ancient Russia, a powder mixture of ash, crushed oak bark and limestone was used for polishing pearls. Woolen fabrics were used to finish the polishing.
Cultured pearls
About two thousand years ago, the Chinese began to use the method of obtaining cultured pearls. To obtain such pearls, they placed various small objects inside the shell with the mollusc. After getting into the shell of this small object, the process of pearl formation began: the mollusc enveloped this object with a thin film of mother-of-pearl, then again and again. After the sink was folded in wicker baskets, and the baskets were lowered into the water for a certain time (from several months to several years).
It is believed that the large-scale production of cultured pearls was started by the Japanese Kokichi Mikimoto. In 1893 he was able to obtain pearls grown in an artificial way. To obtain the pearl of Cociti, Mikimoto used the ancient Chinese method, but instead of any small objects placed inside the shell, mother-of-pearl beads were used. Such pearls even specialists are difficult to distinguish from natural ones.
Methods of obtaining synthetic (artificial) pearls
In addition to cultured pearls, the world is widely produced fake (synthetic) pearls. There are many ways of obtaining such a false pearl. One of the most frequently used methods is the production of hollow, thin glass beads. Under pressure, pearls are pumped into these balls, often other fillers are also used. Fake pearls are different from the real weight (the real heavier) and its fragility. Also, one-piece glass balls are produced. They are covered with dyes (identical to mother-of-pearl) and to fix the color with varnish.
Because of the strong development of ways of making jewelry "under natural pearls" it is difficult even for quite a few specialists to distinguish natural pearls from fake without special means.
The difference between this and fake pearls
The methods by which you can distinguish from the fake natural pearls are divided into two groups: "folk" and "scientific".
Popular ways:
- One of the simplest ways to distinguish natural pearls from synthetic (artificial) is to hold a pearl on the tooth. The real pearl will squeak at the same time.
- If a real pearl is thrown on a solid surface from a small height, then because of its high density it will jump like a ball of table tennis (ping-pong). Artificial (fake) pearls do not possess this property.
- Also, you can take a sheet of cardboard, cut out a hole in it smaller than the pearl being examined. Put a pearl in this hole and bring a sheet of cardboard to the light source. A cultured pearl can see a glowing layer of mother-of-pearl and a dark seed nucleus.
- Putting a cultured pearl in an electromagnetic field, it will turn and take a certain place, while the real pearl will not move.
- There is an opinion that in ultraviolet rays cultured pearls glow green, and the present - blue.
- Detect fake pearls can be, after examining through a 10-fold magnifier hole in pearls (if any) and discovering the separation between the core and the surface layer in the form of a thin, darkish strip. You will understand that you have cultured pearls in front of you. Observing the hole in the cultured pearls are often seen chipped, because it is softer than natural.
Scientific methods:
- An X-ray image of cultured pearls clearly shows the band between the core and the grown layer. If there is no nucleus, then there is a cavity in the center of the pearl. Almost the same result we get using the method of radiography.
- When immersed in a liquid, density 2.7, natural pearls do not sink, unlike a false one.
- Cultured and real pearls under the microscope observe a scaly surface, in the case of fake ones, a smooth surface.