1. Gravity test: there is a measure of the specific gravity of the precious stones on the market; we can use 3.32 of the liquid to test the authenticity of diamonds. The proportion of natural diamond is 3.52, all natural diamonds in the proportion of water will sink, so all floating in the water on the gem, it is certain that it is not a diamond.

2. Penetration observation: the diamond has a high refractive index, and the higher the refractive index of the diamond, the stronger the light reflection, the relative perspective is lower. Can prepare a picture of a line of paper, will be the two unknown diamond determination, face down, cover in a straight line, the diamond back directly to the naked eye can see straight down, such as the pressure in the diamond under, certainly not a natural diamond.

3. Pro oil method: Diamond oil has a kind of "oil absorption", fake diamonds are no such characteristics. The diamond in the face with some trace of grease, friction with the thumb of the diamond, the thumb will feel a kind of adhesive, not easy to slide, and counterfeit diamond will make thumb with slippery feeling.

4. Breath test: natural diamond heat transfer ability, fast heat dispersion. To test a diamond near the mouth, gently blowing, the tested diamond covered with a layer of mist, then immediately look at the diamond misting situation, such as natural diamonds, the fog will be immediately dispersed, and the mist will maintain for a while in the fake diamond, to disperse.

5. Measure and weight: 1 carats of natural diamonds, diameter of about 6.50 mm (0.65 cm), most of the counterfeit diamond in the same 1 carat weight, the diameter size and the total natural diamonds had a big gap.