It is all just metal. The moment we tow an asteroid in, or start mining one, all gold on Earth is worthless, as the demand will be outstripped by the supply.
Unless there's a new gold cartel in town, ala diamonds.
Gold has a pretty widespread industrial use and is in a lot of electronics. You wouldn't have been able to type your post out without gold :)
De Gold's.
Gold is very good, but it isn't the only alternative, even if the current best. If all gold disappeared, do you think they would use something else?
We can build a particle collider and do modern alchemy.