Look at the hardness Crystal is very hard. You can draw a line on it with a stone. If it has no scratches, it means it is a good crystal. On the contrary, its quality is not good.
The second point is to put the crystal vertically in the sun. If a rock crystal looks at him from any direction in the sun, it will shine brightly, which is beyond the reach of inferior crystal.
Thirdly, during the formation of rock crystal, due to the change of environment, when you put it in the sun, there will be even and tiny catkin-like impurities. However, artificial crystals are synthetic, and when you irradiate them, there are often no catkin-like impurities.
The fourth point is color. As long as any kind of gem is colored, we should pay more attention to it. For example, if your crystal is pink, then pink is the best color, and secondly, it can't contain shades such as gray, black and brown. If it is yellow, it cannot contain green, blue, lemon and other colors.
Finally, I wish you buy your favorite crystal.