I remember one could exchange minerals for crowns. Just forgot doing it, now I have, as The Houseplant would say, "a hundred billion, million, trillion....Ah, you know the thing" of those things. Doesn't seem to be the case any longer. What happened?
I believe it was removed when they added sprites into the game, since you now use 3 of 5 of the minerals to craft the sprite food the other 2 are just useless now