How so ? Gold isn't just a currency/exchange medium, it's a valuable material on its own in many ways. Neither bitcoins nor dollars are, they're not commodities turned currencies, they were always meant to be currencies and nothing else.
Let's say you want to go buy a loaf of bread. How do you pay for it with knowledge of energy sources? I'm quite sure the cashier would be quite tired after performing the 300th viva of the day.
Some people do trade knowledge of energy sources for stuff, using money as an intermediate store of value, but most people cannot, and it wouldn't be desirable either otherwise we wouldn't have a varied and healthy economy.
By own material value do you mean for electronics, and thus for us now ? But what about centuries ago ?
Someone suggested me that gold doesn't rust and that stability was interesting as a long time token. But I don't find any usage beside the social status gem.
It works particularly well as a social status gem, because it's at the same time malleable (ie. easy to work with), shiny-looking, and not easily corroded. It's relatively easy to authenticate (compared to a bitcoin for example), and seriously hard to fake (unlike, say, a dollar).
Anyway the point wasn't the merits of gold over currencies, just pointing out the fact that it has a real status as a useful commodity, in a way that purpose-built currency doesn't. That means, among other things, that demand for jwelery in India for example, or changes in electronics manufacturing processes are bound to affect its price.
That makes it quite different from other currencies.
