I ran across an article a while back about the 1 pound coin counterfeiting problem, and fluorescent tagging technology present in 2017 dated coins and afterwards. There’s not a whole lot of information on the subject (security thru obscurity), but I was able to find some patent information the Royal mint applied for. https://patents.justia.com/assignee/the-royal-mint-limited They mention upconverters, downconverters, or phosphors as being embedded in the coin plating, or some other possible technology. Curious if anyone has looked into this? Or would have ideas on how to detect it. It seems maybe uv light or lasers may be needed to activate the tagging technology. I kinda wonder if the silver eagle has this technology as well. When the 2022 ase came out there was similar super “security feature” and nobody mentioned anything further.
If nobody knows about it, what use does it have to those of us transacting with them. The whole point of these security devices is making them known to the public so we don't accept counterfeit bills for instance, in our daily transactions.
Casinos have something like the phosphors on higher denomination table chips they check with a blacklight.
Thanks @masterswimmer and @rte. I think they don’t talk about the hidden features in the same way the 3rd party grading companies used to hide other “tells” about real vs fake coins. Like the 3legged buffalo had other die characteristics they used to keep hushed to make it easier to authenticate. I didn’t know casino chips had added security features seen with uv. Good to know. Maybe I’ll buy some different wavelengths of uv lights and go from there.
