List of unlocked artifact rewards
I'm trying to see the artifact rewards that I have already unlocked. I checked all info screens such as artifacts, research and even notifications, but I cannot find it. Am I blind or is this currently missing?
From this thread, it doesn't look like this is currently a feature (though it seems like it would be greatly appreciated)
I don't think there is any such list of unlocks-you-have-already-gotten from combining artifacts.
I realize this probably isn't what you are looking for, since it is not in-game, but here is a list of all artifact rewards.