My wife made the mistake of saying "Diamonds are stupid," before we were married. Sorry boys, they don't make 'em like that any more.
I've bought her a few over the years, but she hardly ever wears them. When you think about it, diamonds are a self-invented industry with a self-perpetuating market.
If their rarity is what makes them so valuable, how does every fleabag town on the planet have a jewelry store with a few zillion of them on display?