As long as it is sold in a jewelry store, it won't be fake. If they sell fakes, they will be stupid, and the industry and commerce will find someone. You know, once found, the fine is not just tens of thousands, but millions. Do you think anyone would be so stupid? The sound is brittle or hollow. You can also test it with fire. But you can't use a lighter to probe the bottom of the fire, you can only use professional tools. Burning with a lighter, whether true or false, will turn black.