Unfortunately, realizing this is not enough. You need your partner to realize it too, or you're out of luck. Good luck presenting a ring of ruby or sapphire; even though they are far prettier stones IMHO, every girl I've met has diamonds stamped into her heart.
This was an eye opening experience for me as a younger nerd, something that taught me how truly irrational many humans are. Diamonds are clearly pretty, but buying them props up a cartel and indirectly leads to warfare, enslavement, and death. Clearly a young woman would happily understand why I would have ethical objections to this... ...and to this day, I don't understand how some people's minds even work. (It was…
If people stopped buying diamonds, it would be a disaster for the continent.
Saying that, I still would hate to buy something that may have been mined by a slave and purchased by a cartel.