Board Thread:General Discussion/@comment-3123266-20140303175822/@comment-3123266-20140423032020

In my original post, I presumed that when Thor took Loki back to Asgard, Thor brought Loki's Scepter along with the Tesseract. Now that we know the Scepter is left on Earth, we have to entertain the possibility that the Scepter may be powered by another Infinity stone, because Thor wouldn't want two Infinity stones kept on Asgard. Maybe Thor figured one of the stones would be safe with SHIELD, which is probably why Asgard let SHIELD keep the Tesseract for 70 years (and in Norway for centuries before that).

Anywho, I think it is possible that all stones have similar capabilities, it just that each stone is its own unique energy source: Tesseract is gamma, Aether is darkforce, Scepter is ???, Orb is ???