Board Thread:General Discussion/@comment-3123266-20140303175822/@comment-2127388-20140706212519

"Stone" does not have to look like some simple stones that you can pick up in the field. It may be more phylosophical, like a saying "these are stones that are the foundation of...". It doesnt have to be stones literally, but something that is elemental for the thing, and Infinite Stones may be interpreted in this way and the universe.

My theory is that the Stones are all containers (even Aether as gaseous liquid) for the energy which is than absorbed/embedded into the Gauntlet when the time comes. That they hold the actual Gems inside I am not certain, because of the gems on Gauntlet. Unless these are fake made by Asgard to dont make the Gauntlet look "blank". There is not enough facts to presume for more certainty either theory and possibility.

Thanos most likely is aware of Aether on Earth. Either Loki told him, some of his agents told him, Collector told him, or (highly speculative and theoretical) Thanos may be even sensing the Stones. Not knowing their location, but if it is active or not. He is a galactic warlord of immense power, one never knows :) I am still convinved Collector is allied with Thanos, if not that he has his own agenda (he is "collector", after all, and having 6 most powerful objects in existence... who could resist this collecting challenge?).