I was researching a topic very similar to this. How the Spartan used spoiled iron bars or disks to protect the people of Sparta from the trap of using precious metals that gets concentrated in the hands of very few people. In Plutarchs book "Lives of Noble Grecians and Romans" talks about how the king of sparta Lycurgus views that if you make the coin out of a material of little value and make it heavy its very difficult and almost worthless to steal. Much like what you talked about in your video. Thanks for the post.