When the market sees the emergence of an overt Gold bourse - of Gold regaining its primordial status as money on the world stage - Gold will be repriced. And so will the dollar.
Gold and Silver are not “cash”. They are metals — a commodity that has traditionally been desirable regardless of it’s true value or usefulness, and therefore something that has been used in barter exchanges.
Cash is an artificial construct to track barter exchanges without having to directly exchange items of value. Cash itself has no “value”, except as it is acceptable as a ledger to keep track of barter exchanges. Cash requires that we set a value to each thing we want to barter, and that this value be somewhat generally accepted — but rather than go through that hassle, we usually instead set a “value” on the cash instead. So if you don’t think an item is worth what someone else does, you can offer less cash for it, and each exchange can value items accordingly.
This is problematic if you don’t have a system in place already obviously, because someone isn’t going to take your cash if they don’t have some reasonable expectation that it has the same “value”, and will have a similar value when used later. We talk about cash being valued based on how much work it takes to earn it — that’s probably the best measure.
Gold could be “cash”, and was used as cash because it couldn’t be easily created, and therefore there was less danger that someone could cheat and create cash rather than getting it by exchanging a good or service for it.
But gold was a poor cash substitute, because there really is no rational basis for measuring the “value” of an economy based solely on how much gold you can pull out of the ground. Gold couldn’t keep up with the economic value, and so it’s price (value) fluctuated wildly, making it a poor choice to measure the exchange of goods.
Cash of course can be created by the government. On the other hand, imagine what would happen if tomorrow someone stumbled across a gold mine of epic proportions, such as had never been found before, and effectively increased the global gold supply by 10%, within a single country. Would the world accept the instant improvement in that one country’s “value”, or the corresponding destruction of 10% of the current value they held in gold?