I am an author writing a story set in the Stone Age. I know some South American civilizations knew about metal and smelting, but lacked the mines to do it on a large scale.

So from the point of view of, say, a proto-European or middle easterner in the Stone Age, would it be erroneous for me to describe something as “silvery”?

Would they know what metal is, even if they didn’t quite know what to do with it? Or would they just have no idea?