These days we pretty much take it as a given that gold is more valuable than silver. The obvious example is the Olympics and other such competitions that give "gold" medals for first place and "silver" for second.

When I was younger I read somewhere that silver was actually rarer than gold in Europe, up until the Spanish started exploiting the New World silver mines, and the massive infusion of silver into Europe devalued it.

I haven't ever seen that stated since, so I doubt its true. However, I did find a reference that silver was in fact rarer in Egypt during the Old Kingdom.

So it seems there probably were extended periods in literate areas where silver was more valuable than gold. What (and when and where) were they?