Converting basic resources to luxury resources

[lordrune]

I'm wondering if there's a way to convert some of the basic resources - things like coral, resilin, gold, from being simply bonuses on tiles, to being tradable luxuries, that give a global boost to happiness healthiness that confused mechanic that they should just call welfare. Obviously Civ BE turned this part of the Civ 5 code off... does anyone know if there's a realistic way to turn it back on?