I have tried to look for an answer using the [currency] tag but none of those questions had answers that sufficed.
I understand that back then there were a myriad of currencies, most of these were based on silver and gold, and their value in said ore usually represented their denominated value as well. (at least this is what I assume, correct me if I am wrong).
At some later point the denominations value was provided by an other backing aside of what the actual coin was worth, but my question is more about when a gold coin's worth was governed by the gold that was used to smith it.
Say there are two kingdoms, each mint gold coins. Crowns and Florins as an easy example. Trade is plenty between said kingdoms so there have to be conversions of the currency going on.
Now if the currencies have different shapes and thickness I assume one coin type would be worth more than the other, if looking at the metal value. How is this difference in worth handled by the converters? I read a lot about using scales and we all know the stereotypical image of somebody biting a coin to check if it is fake, but this can't be how it was done surely?
Additionally, how can they check if a coin had a core of another metal (of less worth) but a coat of gold?
And for the kingdoms, how could they be sure their coinage was not devalued? I could think of some tactics to weaken a kingdom by tampering with their currency. Chaffing gold off their coins, forging them with a lower gold content and trading them out to melt their actual coins, and so on. These are things I come up with and I have little knowledge about it. I guess somebody with more extensive metallurgical knowledge can think of plenty more things to do.
- How did they make conversions between two currencies in the middle ages (and other appropriate times) with currencies which's denominations values were the actual metal value of the minted coin? (backed by the metal and not the state or something)
- How did the converters handle forgeries and tampering with the coin?
- How did the kingdoms/ empires/ ... handle their currency being tampered with and exploited? Did this happen at all?