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Vincent reluctantly introduced it to Qin Shiou, saying that as technology develops more and more, there are more and more methods of counterfeiting, making it much more difficult for jewelers to identify black pearls.
There are currently four main methods for cultivating black pearls: silver salt treatment, radiation, dyed bead core, and film coating.
The most commonly used method is the first one. Vincent called a staff member in a white coat to demonstrate to Qin Shiou. This method involves soaking pearls in several reagents. After soaking for a while, the staff member He took it out and said, "This is a solution of silver nitrate and dilute ammonia, which can cover the surface of the pearl with a silver coating."
Then he put the silver-white pearl into a sealed container and irradiated it with strong light. Slowly, the color of the black pearl changed from white to black.
"It contains hydrogen sulfide, which can undergo a reduction reaction with the chemicals 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 complicated and take a lot of time. Being longer, the black pearls produced are more realistic.¡±
Qin Shiou gave a thumbs up and said: "Human wisdom is really infinite, and fraud can be so technical. The 21st century is indeed an era of science. I have to go to university to study."
¡°Learn how to fake?¡± Vincent joked.
Qin Shiou chuckled. In fact, he felt a little guilty because his black pearls were also a bit fake. Another common method of counterfeiting was bead core dyeing. The bead core was dyed black and then implanted into the pearl oyster. During the formation process of the pearl, the pearl oyster was continuously added to the pearl oyster. By adding melanin preparations, the final pearl will be pure black.
Because pearls grow too slowly, he put small pearls in the black butterfly oyster. The black pearls were surrounded by substances secreted by the black butterfly oyster.
The experts hired by Vincent demonstrated to Qin Shiou two other methods of counterfeiting. One is to irradiate pearls under gamma rays from a cobalt source to turn them black. This is the ray radiation method. The last one is film coating, where a thin layer of black glue is applied to the surface of the pearl
While Qin Shiou watched these demonstrations, one hundred and twenty-eight black pearls were assigned to different experts, and they began to identify them.
We still start with physical identification, looking at the color first. This time we use an instrument similar to a microscope. It has a bracket that can hold a circle of eight black pearls at a time. After putting the black pearl on, the bracket will hold the black pearl up, and then there will be several rays of light scattered on the black pearl from all sides.
Vincent explained: "There are no two identical leaves in the world, and there are no two identical black pearls. Natural black pearls have different colors from light gray to black, and its beauty lies in the tone of its look. Color accompaniment. Under astigmatism, if you slowly turn the black pearl, you can see a slight flash of light changing, just like a rainbow."
Qin Shiou stared at the black pearls carefully, then shook his head awkwardly and said: "It seems that this requires professional vision, I can't see it."
Vincent laughed and said: "Of course, of course you can't see it, because you have to use a ten-fold mirror to see 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 special shapes, such as pear-shaped, drop-shaped, dumbbell-shaped, etc. The black pearls Qin Shiou brought here are almost all perfectly round, which is why they are so valuable, with one pearl costing tens of thousands or hundreds of thousands of dollars.
At this point, Vincent joked again, saying that when he first saw the excellent shapes of the black pearls he provided to make the Queen of the Night, he subconsciously thought they were all cultured black pearls, so he did not come to see Qin Shiou, otherwise He must entertain such a potential customer well no matter what.
Qin Shiou smiled and said: "Perhaps they are really cultured pearls, because they are all cultured in my fishery."
Vincent also laughed, and then asked in a seemingly casual tone: "With so many high-quality black pearls, I'm afraid Tahiti's annual output is no more than this. Qin, how did you get it? Don't tell me, Your fishery has more black butterfly oysters than Tahiti."
Not all black butterfly oysters can produce black pearls. According to probability statistics, the probability of producing black pearls in Tahiti is one in 10,000. In other words, only one in 10,000 black butterfly oysters can brew black pearls. ! It¡¯s not clear what kind of black pearls are produced in this way. They may be irregular in shape or poor in color, so there are very few high-quality black pearls produced every year.
This is also the reason why the price difference is so big. Imitation pearls only cost a few dollars each, while cultured pearls only cost a few dollars.It only costs tens or hundreds of dollars, while wild pearls usually cost thousands of dollars, while top-quality natural pearls definitely cost 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 powerful, there is always the possibility of mistakes. Of course, precision machines are not completely reliable, but with the expert's eyes and the judgment of precision machines, the final result is very reliable.
So, later Vincent introduced a series of black pearl identification techniques to Qin Shiou. There are four main types, each targeting the same counterfeiting technique.
The first is the ultraviolet fluorescence test, which is for film coating technology. Use a light machine to emit ultraviolet light on black pearls. Under ultraviolet light, black pearls often fluoresce and change color, ranging from bright red to coffee red, which is extremely gorgeous. Because there is a layer of black gel on the surface of film-coated pearls, most of them do not react to ultraviolet light.
The second is X-ray photography and inspection. Vincent said that this technology is specifically used to determine whether cultured pearls have been dyed with silver salts. After taking black pearls with Pearls can be distinguished by a circle of light white between the nacre and the core of the 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 when exposed to X-rays. Using a spectrometer to measure the wavelength, you can identify whether it is a pure black pearl or a cultured pearl made by X-ray radiation.
The last one is the infrared photography test. This test is for cultured pearls made with dyed bead core technology. The penetrating power of infrared rays is extremely strong and can penetrate into the pearl core. If it is a cultured pearl, because the texture is uneven, the angle of the infrared ray will change after penetrating the black pearl and then emitting.
This is what Qin Shiou is most worried about, because some of the black pearls he has here use other types of pearls as pearl cores! (Remember the website address: www.hlnovel.com