A purple flashlight is used to look after whether the surface has a fluorescent reaction. Normal sea yellow will not have fluorescence reaction. Only the glued sea yellow bracelet can see the fluorescent reaction on the surface. Glue is not fake, it is to make the surface of beads brighter, but such bracelets will be shoddy, and long-term contact with the skin is not good for your health.
Therefore, the purple flashlight can not identify the authenticity of sea yellow, but can identify whether the surface of beads has been optimized.