I kinda like the idea of the electrum coins. I guess that means they just coined the metal just the way they found(mined)it without mixing
Actually, they didn't. While the use of electrum coins clearly evolved from the use as primitive money of naturally-occurring nuggets of electrum, chemical analysis of naturally occurring electrum found in the rivers of Lydia comes up with a composition typically around 70% to 90% gold. The electrum coinage, on the other hand, starts out at a consistent 55% gold and falls to around 40% by the end of the electrum coinages. The consistency of the composition in the coinage at any given time implies that the "electrum" was therefore produced by mixing relatively pure gold and silver, in known proportions.
TL;DR: it turns out the coins are actually made of "synthetic electrum", that had less gold in it than naturally-occurring electrum.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis