Chapter 399 It is too difficult to identify the true and false gold bars
Looking at Zhao Manfu's angry look, Zhou Wencheng actually thought of the beautiful woman Xiao Wang of China Construction Bank packaging him with gold bars again.
This is not God's will, what is it? Since God has given me a chance, I naturally have to seize it.
Zhou Wencheng comforted Zhao Manfu and said, "Mr. Zhao, don't be angry. I think this packaging seems a little naive. At that time, I didn't find this flaw when the bank staff packed it.
For us, packaging is a trivial matter, and if the gold bar is really, there will be no problem.
It is more important to be authentic or fake gold bars.
Mr. Zhao, just open it and read it.”
After hearing Zhou Wencheng's words, Zhao Manfu opened the packaging box of the gold bars, picked up the gold bars and checked them out in a pretentious manner.
Finally, he put down the gold bar and said, "I don't know how to use the method to test the authenticity of the gold bar.
I bite it with my teeth on TV. Your gold bar is too big and I can't bite it."
Zhou Wencheng smiled and said, "Forget it, I'd better ask the professionals."
After saying that, he took out his cell phone and found the phone number of Xiao Wang, the first branch of Nanshan Construction Bank, in his address book. After dialing, he said, "I am Zhou Wencheng, the one who just bought gold bars."
A surprised voice came from the phone and asked: "Hello, Mr. Zhou, is it fake that you checked so quickly for the gold bar?"
Zhou Wencheng smiled awkwardly and said, "No.
Because this gold bar is very important to us and must not be fake. We want to verify it, but we don’t understand the verification method.”
After saying that, Zhou Wencheng turned on his phone as a hands-free one and placed it on the coffee table between him and Zhao Manfu so that both of them could hear the communication content of the phone.
"So, I guess what you meant by calling me was to ask someone who sells gold bars to you to teach you how to verify the authenticity of gold bars, right?"
"Yes, that's the idea."
"Then, can you believe what I said, wouldn't you think I was talking nonsense to sell fake gold bars?"
"I believe you won't lie to me."
"Okay, it's your brain circuit."
"I'll just explain it to you."
"You have watched costume TV series. Is there any bite marks inside that are gold?"
"Yes."
"Then you take it out and bite it now, how about you?"
"Really bite?"
"Of course, this is the easiest way to identify it, do you understand?"
"I don't understand, I'd better bite it."
"Some bricks say that real gold usually leaves a faint tooth mark after biting with their teeth. This is because gold with high purity is a little soft, and impure is hard and cannot make tooth marks."
"I have some tooth marks, it seems to be real gold."
"Don't worry, the expert hasn't said it yet."
"Then you continue."
"Experts say that the Mohs hardness of human teeth is 6, the relative Mohs hardness of gold and silver is 2.53, pure copper is 3, and iron is 4.
Therefore, the Mo-type hardness of gold, silver, copper and iron materials is not high. If you bite hard with your teeth and bite hard, as long as you use enough force, you may leave a conspicuous tooth mark.
To sum up? Using human teeth to mark the authenticity of gold? There is no scientific basis for finding it."
"Ah? That's it, no, this piece of gold has been bitten, I want to return it."
"You bite yourself? What's up to me?
Are there any other identification methods? Do you want to continue listening?”
"Why don't you listen?"
"Do you have a magnet in your hand?"
"Not now? If you need it? Just go find one later."
"A magnet can test the authenticity of gold.
If gold products contain other metal impurities? Use iron-sucking stone to suck it. If it can be sucked up, it means that gold has more impurities, which is adulterated gold.
This sentence is true.
But scientific knowledge tells us that there are only three metals: iron, cobalt and nickel, which can be sucked up by magnets.
So? If the gold counterfeiter adds three metals: iron, cobalt and nickel, the magnet method cannot detect it."
"Hmm? This can be understood.
Find a magnet to suck it later. If it sucks up, you must find a return item."
"Okay, if it is sucked, it will be backed. However, if there are tooth marks, you must restore it to its original state."
"Is there any other identification method?"
"Yes. Generally, density measurement algorithms can be used to eliminate some adulterated gold.
The gold density is at room temperature ranging from 19.26 grams/cubic centimeter to 19.37 grams/cubic centimeter.
You can choose a measuring cup with higher accuracy and put a regular amount of water, such as 200 ml.
When putting the gold bars into the water, it should be noted that the gold bars must be completely submerged.
Measure the volume of new water to get data, for example, 350 ml-200 ml=150 ml.
This 150 ml is the volume of the gold bar.
Knowing the mass and volume of gold bars, the density of gold bars can naturally be calculated smoothly.
If the calculated density of the gold bar is within the range of the standard value, then the gold bar is more likely to be of higher quality, otherwise it may be adulterated.
It should be noted that this method can exclude most adulterated gold.
However, if adulterated gold is strictly followed, scientifically add other suitable metals.
We can't tell.
For example, counterfeiters incorporated two metals: iridium and tungsten. Their specific gravity is similar to gold, and they cannot be identified by measuring density alone."
"Well, I understand, this is the density method, are there any other simple identification methods?"
“There are simple ones.
Physical bending can also be used.
This method is suitable for gold bars in thin-sheet process. Before purchasing, you can bend the gold bar itself with your hands.
If the gold bar has a high purity, like a thousand-legged gold, the gold bar can be bent.
If the purity of the gold bar is low and the color is different, then the bending difficulty will be higher. It is difficult for ordinary people to use it with bare hands to make the gold bar bend."
"It is not suitable to use this method like me, and I can make any mistakes."
"I'll brag all the time, can I bend it with a steel bar?"
"It's really possible. I was curious whether the gold bars would be broken?"
"Don't worry, don't worry, no matter how fake gold bars are, they will still be a little bit golden. The ductility after the compounding is also relatively good. I haven't heard of anyone holding fake gold bars with bare hands."
"I understand this method, please talk about the next method."
"The next method, I guess you prefer."
"Oh, let's hear it."
"This method is: the fire method.
When the gold bar is melted with a high-temperature flame, other impurities will naturally separate from the gold bars.
This method can accurately detect whether the gold bar is adulterated.
But it also completely destroyed the craftsmanship of the gold bar itself.
This method depends on whether it is applicable to you."
"It's too inapplicable. If it burns out, it will turn into a golden lump. It's so ugly."
"It's really a bit ugly. I've been talking about it for so long. Wait until I drink a sip of water and then relax."
Zhou Wencheng quickly mutes the microphone of the phone and asks: "Mr. Zhao, it is too difficult to identify the authenticity of gold bars. Do we still need to continue consulting?"