1639. High Technology without Dead Ends

Vincent reluctantly introduced to Qin Shiou, saying that the development of science and technology is getting more and more advanced, and there are more and more methods of counterfeiting, which makes it much more difficult for jewelers to identify black pearls.

Now there are four main methods of cultivating black pearls: silver salt treatment, ray radiation, dyed bead nucleus, and film coating.

The most used method is the first one. Vincent called a staff member in a white coat to demonstrate to Qin Shiou. This method is to soak the pearls in several reagents. After soaking for a while, the staff member will He took it out and said, "This is a solution of silver nitrate and dilute ammonia, which can coat the surface of pearls with a layer of silver plating."

Then he put the silver-white pearl into an airtight container and irradiated it with strong light, so that slowly, the color of the black pearl changed from white to black.

"It contains hydrogen sulfide, which can undergo a reduction reaction with the chemical substances in the coating under strong light, turning the silver-white coating into black. Of course, this is just a demonstration. In fact, the steps are more cumbersome and time-consuming. Longer, the resulting black pearls are more realistic."

Qin Shiou gave a thumbs up and said: "The wisdom of human beings is really infinite, and fakes can be made with such technical content. The 21st century is indeed an era of science. I have to go to university for further study."

"Learn how to fake it?" Vincent teased.

Qin Shiou laughed. In fact, he was a little guilty, because his black pearls were also a little fake. Another common method of counterfeiting was bead nucleus dyeing. After the bead nucleus was dyed black, it was implanted into the pearl oyster. Add melanin preparations to the pearls, and the final pearls are pure black.

He used to put small pearls in the black butterfly shell because the growth of pearls was too slow, and the black pearls came out only after the black butterfly shell secreted substances to surround them.

The experts brought by Vincent demonstrated two other counterfeiting methods to Qin Shiou. One is to irradiate the pearls with cobalt source gamma rays to turn them black. This is the ray radiation method. The last one is film coating, which applies a thin layer of black gelatin to the surface of the pearl...

While Qin Shiou was watching these demonstrations, one hundred and twenty-eight black pearls were distributed to different experts, and they began to identify them.

It still starts with physical identification. Let's look at the color first, this time using a microscope-like instrument with a bracket that can hold a circle of eight black pearls at a time. After putting the black pearl on it. The bracket holds the black pearl up, and then there will be several rays of light scattered on the black pearl from all around.

Vincent explained: "There are no two identical leaves in the world, and no two identical black pearls. Natural black pearls have different shades of color from light gray to black, and its beauty lies in the difference in tone. With color.

Under astigmatism, turn the black pearl slowly. It can be seen that there are slight flashes of light constantly changing, like a rainbow. "

Qin Shiou stared at the black pearls carefully, then shook his head in embarrassment and said, "It seems that this requires professional vision, and I can't see it."

Vincent laughed and said, "Of course, of course you can't see it, because you have to use a 10x mirror to watch it."

This microscope not only observes the color of black pearls, but also measures its roundness, diameter, brightness and other parameters.

Vincent said that wild black pearls rarely produce particularly round types, and almost all have some abnormal shapes, such as pear-shaped, drop-shaped, dumbbell-shaped and so on. The black pearls that Qin Shiou brought were almost perfectly round, which is why they were so valuable. A piece costs tens of thousands or hundreds of thousands of dollars.

Speaking of this, Vincent joked again, saying that the first time he saw the black pearls he provided to make the Queen of the Night were so good in shape, he subconsciously thought they were all cultured black pearls, so he didn't come to see Qin Shiou at first, otherwise Such a potential customer, he had to entertain him no matter what.

Qin Shiou said with a smile: "Maybe it's really cultured pearls, because they are all grown in my fishery."

Vincent also laughed, and then asked in a seemingly casual tone: "There are so many high-quality black pearls, I am afraid that Tahiti's annual production is no more than this, Qin. How did you get it? Don't tell me, You have more black butterfly shells in your fishery than in Tahiti."

Not all black butterfly shells can produce black pearls. According to probability statistics, the probability of Tahitian black pearls is one in 10,000. In other words, only one out of 10,000 black butterfly shells can brew black pearls! And the black pearls produced in this way are not sure what they are, they may be irregular in shape or poor in color, so there are very few high-quality black pearls that can be produced every year.

That's why prices vary so widely, with imitation pearls costing as little as a few dollars each. A cultured pearl only costs tens of hundreds of dollars, wild pearls usually cost several thousand dollars, and the price of the best natural pearls must be tens of thousands or hundreds of thousands of dollars.

The most important thing about physical testing is machine testing. Although the eyes and senses of treasure appraisal experts are very good, there is always the possibility of misjudgment. Of course, precision machines are not completely reliable, but with the eyes of experts and the judgment of precision machines, the final result is very reliable.

Therefore, Vincent later introduced a series of black pearl identification techniques to Qin Shiou. There are mainly four types, each of which is aimed at the same counterfeiting technique.

The first is the UV fluorescence test, which is for thin film coating technology. Use a light machine to shoot ultraviolet light on the black pearls. Under the irradiation of ultraviolet light, the black pearls often have fluorescence, and the color changes, ranging from bright red to coffee red, which is extremely gorgeous. Film-coated pearls do not respond to ultraviolet light because they have a layer of black gelatin on the outside.

The second is X-ray photo inspection. Vincent said that this technology is specially used to judge whether cultured pearls have been dyed with silver salts. The pearl can be distinguished, and there is a light white circle between the nacre and the nucleus of this pearl.

The third method is called X-ray fluorescence test, which also uses an X-ray machine, but instead of taking pictures, it emits light. All jade can emit radiation of a specific wavelength under X-ray irradiation. Using a spectrometer to measure the degree of the wavelength can tell whether it is a pure black pearl or a cultured pearl made of ray radiation.

The last one is the infrared photography test, which is aimed at the cultured pearls produced by dyed bead nucleus technology. Infrared rays have strong penetrating power and can penetrate to the pearl nucleus. If it is a cultured pearl, because the texture is uneven, the angle of infrared rays will change after penetrating into the black pearl and then emitted.

This is what Qin Shiou is most worried about, because some of his black pearls use other types of pearls as pearl cores! (To be continued.)

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