I think there is a substantial amount of magical thinking that leads people to specifically value gold or silver, and advance justifications for those metals as currency standards after they've already made up their minds. If they were starting from their claimed justifications, and simply looking for durable, rare substances whose production is limited and cannot be rapidly increased, then I'd expect as many cries for the Selenium Standard as the Silver Standard.
There's nothing magical about it. Gold and silver have thousands of years of historically being accepted as money therefore it's likely to continue that way. Whenever the free market decides what it will use as money, it settles on gold and to a lesser degree, silver and other metals. That's what I'm more interested in, free market money, rather than any specific metal. Let the market decide. Historically, it's been gold. What's the point in trying to fight that? Just so you can seem sophisticated?