“‎...Gold is gold everywhere, fungible and indifferent. But when a disk of gold is stamped by a coiner with certain pompous words and the picture of a King, it takes on added value -- seigneurage. It has that value only in that people believe that it does -- it is a shared phant'sy.”

- Neal Stephenson, The Confusion

Good discussion in Wired interview: https://www.wired.com/2004/04/clearing-up-the-confusion/