It is invisible. But a golden coin on posters is used for purposes of advertisement. It  10  is also said that the word ‘mining’ in the digital creation of the bitcoin and altcoins is used to give the impression that it’s gold that is being mined. Still some others argue that it’s a convenient means to avoid income tax and VAT payments.
Central bankers have been seeing this game differently from afar since 2009. What is money? What’s the definition of money? How broad is the definition of money? If cryptocurrencies are money, anything else can, of course, be construed as money. Take for example the banknotes and coins in your wallet. They are an asset owned and held by you.