2. Penetration observation method: Diamonds also have high refractive index. You can also see that diamonds with high refractive index reflect more light, so the relative perspective is also lower. Then you can use a piece of paper with straight lines, and then put the two unknown diamonds on it. Be sure to face down and cover it in a straight line. At this time, you can see the straight line below the diamond, which means it is not a natural diamond.
3. Oil-loving method: diamonds have an "oil absorption" effect on oil. If they are fake diamonds, they do not have this characteristic. You can touch the diamond with a little oil on your face, and then you rub the diamond with your thumb. At this time, you will feel that your thumb is sticky and not easy to slip, but counterfeiting is different and will make your thumb feel slippery.
4. Breathing test: natural diamond has good heat transfer ability and fast heat dissipation. Then you can put the diamond close to your mouth and breathe gently. At this time, you will find that the diamond is covered with a faint mist, and you should also pay attention to the volatilization of the diamond mist. If it is a natural diamond, the fog will spread faster, but counterfeiting is different. It will last for a while before it dissipates.
5. Measurement and weight: Generally speaking, if a natural diamond reaches 1 carat, its diameter is about 6.50 mm 0.65 cm), but counterfeiting is different, its weight will be about the same 1 carat, and its diameter will be somewhat different from that of natural diamonds.