Just in case there was any doubt, here's what Aleksandr A. Malinin, advisor to Alrosa which is the state-owned diamond company of Russia, had to say to the New York Times about these wonderful stones everyone seems to love so much:

“We have to tell people that diamonds are valuable. We are trying to maintain the price, just as De Beers did, as all diamond producing countries do. But what we are doing is selling an illusion,” meaning a product with no utility and a price that depends on the continued sense of scarcity where there is none.

Yes. An illusion. These are rocks, y'all. Pretty rocks, yes. But at the end of the day, they're plain, old ridiculous rocks. Only an idiot would invest in them, think they're forever or equate them with love. And no one wants to be with an idiot.