Gold or Silver Coins
Like happiness, most peoples’ wealth is intangible. It’s just a number that represents a theoretical claim on a few bars of metal locked in a vault somewhere that don’t exist anyway. So what’s better than happiness and fake money? Gold! And nothing but gold! But you’re way too sophisticated to give them a shapeless ball of ore. Gold coins allow you to hand over timeless wealth in a package that’s fit to be displayed. Just like a king of yore.