Thank you for this. I saw your post asking for help buying metals. I'm interested as well, but was wondering how we know we're getting the real thing when we buy. I also wonder if at some point a person decides to sell, if they can sell back to the coin or metal shop they bought from. I hope you find the info you need to feel comfortable with a purchase.
There are tools you can use that zap metal with an electrical charge and a specialized camera looks at the light generated.
Different metals burn at different colors. Copper, for instance, burns green.
A spectroscope splits the light generated and detects a specific signature of light the material puts out.
https://www.youtube.com/watch?v=I9F-28B5FZE
Gold always puts out the same signature. If it is an alloy, it will not look the same. This is what gold looks like: https://upload.wikimedia.org/wikipedia/commons/1/18/Gold_spectrum_visible.png
Thank you for this. I saw your post asking for help buying metals. I'm interested as well, but was wondering how we know we're getting the real thing when we buy. I also wonder if at some point a person decides to sell, if they can sell back to the coin or metal shop they bought from. I hope you find the info you need to feel comfortable with a purchase.