In case you’re trying to keep track of the Infinity Gems;
- Kevin Feige (President of Marvel Studios) stated that the Tessaract seen in The Avengers and Thor was actually an Infinity Gem, specifically the Space Gem.
- The Aether seen in Thor: The Dark World is also one, although it’s yet to be confirmed exactly which one. Personally, I think it fits into the Reality Gem's power area.
- Loki’s Staff, seen in Avengers, Thor, etc appears to have a gem. In Captain America: The Winter Soldier, a scene in the credits shows it being un-assembled digitally, possibly alluding to the gem in it being a Infinity Gem. I’d say it’d be the Mind Gem.
- In Guardians of the Galaxy, the “Orb” item that Peter steals houses a purple gem, said to be the Power Gem by Feige.
That leaves us with just two; the Time Gem and the Soul Gem.
I’m not going to lie: I absolutely DESPISE the idea of Loki’s staff being the Mind Gem. Natasha was able to break its control over Clint with a simple blow to the head. That’s so pathetically weak compared to the power of the Aether/Reality Gem, which has the power to plunge the entire universe into darkness.
The Tesseract is made of the same element as the ‘vibranium’ powering Tony’s arc reactor, however it’s older, far more powerful and has an agenda of its own.
My theory? If Howard Stark was able to take a chip off the Tesseract, why not other beings? They could have broken off a piece then encased it in another magical stone— one that posesses different powers. This would explain the mind control, energy blasts AND it would give the scepter gem a believable connection to the Tesseract.
edit; AND ANOTHER THING:
Thor knew Loki was after the Tesseract thanks to Heimdall’s all seeing gaze. If the scepter did indeed carry the Mind Gem wouldn’t he have gone after it as well??
Also that would mean Thor left the Mind Gem on Midgard/Earth without telling anyone of its true nature. That’s a terribly irresponsible move considering it falls into Hydra’s hands post cap2.
Just so people know, this is what I’m basing The Black Box Heist's Infinity stone lore off of - so I'm NOT basing it on color.