what happens, if i get nutmeg from an admiral and indonesia is in the game and founds a city which produces nutmeg? can that even happen? is my nutmeg not unique anymore then?
What do you mean by not unique anymore? I'm not sure about this, but if Indonesia is in the game, the Luxury Resources granted by Great Admirals shouldn't be any of Indonesia's ones (and the same goes for Brazil). But, even if that could happen, Nutmeg would still be a Luxury Resource, so you'd get happiness from it, you'd be able to trade them with anyone who doesn't have a copy, and you wouldn't be able to get a Global Monopoly bonus either, as these copies doesn't count towards Global Monopolies.
So the only difference would be that Indonesia would be able to trade its copies with other civs as well, and maybe prevent you from doing it with some of them, but that'd be all.
From what I remember seeing in game (can’t check at the moment) is that it simply gives you copies of a random luxury that your current continent does not have access to. I wonder if playing on Pangea then if it counts the entire landmass as a continent.