Friends! First of all, thanks for your time and help.
I'm conducting a research on the word "Mark": it all started in a forgotten language, meaning "forest". Since forests were natural borders, the word modified a bit and its new meaning was exactly this: "boundary". From this, words like Marquis are born—that is, the one responsible for caring for the borders.
This is all happening within a narrow cultural scope (mainly German, France and England), eventually leading to the meaning "sign/symbol", until the marc (unit [the measure for gold and silver]) turns up in my research out of nowhere.
Before it became a unit, the word "mark" became widespread in all nordic cultures, with very similar meanings in Icelandic, Norwegian, etc.
This is an art research, and the question is: Why would a piece of gold / silver have such name? From "border" to "unit", it is one hell of a leap. Were there objects called "mark"? (A coin/ingot with a symbol, for instance.)
All this will end up in the Deutsche Mark, when the name no longer holds an evident association with what I'm researching, being just a convention.
Any sort of reference (text) or visuals (paintings, etc) would be extremely appreciated. Thanks!
Ps: excuse me if this is an easy/stupid question. I’m not a native English speaker, so the more specific a topic gets, the harder the research.