Silver is highly useful. It is used in industry, film, medicine, electronics and more: it has powerful antibiotic properties. I dealt in PMs for a few years and at the time it was estimated that a third of all silver ever mined is used and can not be effectively recovered. It also kills werewolves. Gold has many special properties. It has a durability which makes it almost indestructible, only aqua regia disolves it. It is very maleable; an ounce can be hammered so that it can cover a tennis court. Precious metals, unlike paper, can not me fabricated out of thin air and destroy the accumulated wealth of a nation.