I think Millionaire$ may be on to something with copper. Not sure if playing or not but I take the point with some seriousness. I have been looking for copper bullion bars and coins and they seem decent enough and in similar style (not government mint though) to mainstream collection material.
Copper probably more like the new Silver I think.
Gold/Silver/Copper
Atomically they are all have similar characteristics with their electrons and are aligned on the periodic table of elements.
Set 11 on table.
https://en.wikipedia.org/wiki/Periodic_table
I think one of the scandinavian countries many hundreds of years ago had a copper standard as they had no silver or gold and it was exchanged on a basis with silver and gold. Obviously quantities required too trade sovereign balances at the time made it difficult to settle accounts easily on a cumbersome basis. This in fact led to the very first paper currency backed by copper.
Silver likely to be replaces by copper in electronics by nerds I would think given time and silver price explosion. This is predicted by WEB BOT very recently. This is another tool in my tool box that I use to dissect information levels.
https://en.wikipedia.org/wiki/Web_Bot
Cliff worked on the fringes of the intelligence community I think developing this kind of spider technology. It can be applied to financial markets as well as many aspects of life on earth, human or otherwise. JSNIP4 is worth listening to on YouTube as in a supporter of Cliff's highly intelligent work.
JFI