A few days ago, it was reported that tourist Qin swallowed a diamond worth 2 million yuan at a jewelry exhibition in Bangkok, but others were caught off guard. Later, she was arrested and driven to Japan. Later, when the police checked her passport, they found that the woman was actually from China. They found diamonds in the large intestine with X-rays and took them out through colonoscopy. At the same time, the jeweler was arrested for selling fake diamonds at a high price because the real diamonds could not be found under X-ray.

Although this news was quickly confirmed as a rumor, I believe many people have this idea: can't you find real diamonds under X-ray? Actually, it is not. To find out what happened, let's look at the principle of X-ray inspection. X-ray belongs to high-energy particle flow, which has certain penetration to various substances. If the human body is placed between the X-ray generator and the film, the X-rays in the bones and other parts are seriously attenuated and cannot penetrate. Therefore, the film of the bone can't be sensitive, and there will be images of the bone. X-rays can penetrate fat, organs and other tissues smoothly. The film is photochemically sensitized and the silver halide on the film is decomposed into black silver. This is how to make black, white and gray images in movies.

Diamonds are colorless crystals made of carbon, the atomic number of which is 6, which is very small. If the formula is introduced, it can be found that the attenuation coefficient of diamond is very small, and most of the X-rays pass through the diamond, so it is difficult to directly detect the diamond under the X-ray machine. But just as hospitals need to understand the internal organs of the human body, if people take X-ray contrast agents, the situation is very different. Generally speaking, hospitals will let patients take barium sulfate orally, commonly known as "barium meal". The atomic number of barium is 56. X-rays are difficult to penetrate and appear black under X-rays. In this way, diamonds have nowhere to hide.

In addition, the X-ray security instrument used in the airport has two sets of detector arrays, which can detect high-energy and low-energy ray signals respectively. By comparing these two signals, the effective atomic number of the detected object can be obtained, thus distinguishing various substances. So, obviously, diamonds can also be found. Therefore, because the attenuation coefficient of diamonds is very small, it cannot be said that "no real diamonds can be found under X-ray". In fact, many ore companies use X-ray machines for inspection after work to prevent employees from carrying diamonds.