If gold has no value anymore, if no rare elements exist anymore, this will be a game changer because commodity money will be history, forever. The concept of intrinsic value will be gone.
No, the concept of money-value derived from scarcity of these materials will be gone, which just illustrates how silly that concept was in the first place. This would be just one step closer to the abundance society, which is a good thing. Many rare metals have industrial uses which could far outweigh their their silly use as money in terms of total value to the human race.
That assuming this tech is even feasible in the first place.