You're right that silverware will tarnish much more quickly because of the addition of copper (and possibly other metals) -- so a bad example from me. But whils

You're right that silverware will tarnish much more quickly because of the addition of copper (and possibly other metals) -- so a bad example from me. But whilst pure silver is much more resilient to tarnishing, it will still slowly tarnish because even normal indoor air is prone to contain trace amounts of gasses with sulfur like hydrogen sulfide, which will react with the silver. Whereas I don't think pure gold does. My guess would also be that most people who had school chemistry would order the silver, gold and platinum correctly in terms of their relative reactivity (and value) because this replicates exactly the order of fanciness of credit cards, record sales etc.