I'm curious how pure metals (such as in coins) were by the mid 1500s in Europe. I know that in some cases metal purities are purposely less than what they could be, such as with WWII era US coins, but if they were trying to make it pure what purity could they achieve and was it very standard between coins with the same minting?
I am just kind of curious in general, but what motivates me to ask is that I bought a 1/2 Grosz Sigsmund II from the year 1567.