What is a purple flashlight for?

Purple flashlights are widely used in our lives. We can use the self-control flashlight to detect whether there is fluorescent agent in daily necessities, check the authenticity of valuables such as jade, jade and amber, check whether there is curing agent, whether glue is injected, check banknotes, and distinguish the authenticity of RMB. This is the purpose of exploring tourist purple flashlights.