But these currencies do not have gold backing right now and gold is rising in price like it never did before unless you compare rates of rise over time.
Gold will drop in price not only due to new found confidence in paper currencies but gold would have to be over priced relative to most commodities at the time. However right now just about everyone with any familiarity will say that gold ( like all precious metals) is very underpriced. So gold in also rising to correct the recent undervaluing.
As for silver, for investors to sell much silver into the markets to severely depress the price is less likely than for gold which is an almost completely an investment item. To do so with silver it can not be done with bullion, imo. However it could be done with paper silver, which again imho would be nothing more than artificial manipulation.
Any real metal selling would be met with opportunistic industrial users buying to bulk up for future usage.
Hence my opinion is that gold is more subject to public opinion then silver, actual shortages of silver being the exception. And there are possibilities of severe silver shortages right now.