Currently, the Marvel Cinematic Universe is setting up Thanos for later films, a mad Titan who is supremely powerful thanks to the Infinity Gauntlet, a device worn on the hand that is powered by 6 Infinity Stones or Infinity Gems.

In the comics, these are listed as;

 - the **Power Gem**, which increases the user's physical power, 
 - the **Mind Gem**, which increases the user's psychic and mental abilities, 
 - the **Soul Gem**, which allows the user to control the free will of others, 
 - the **Space Gem**, which allows the user to travel through space, 
 - the **Time Gem**, which gives the user control over time, and 
 - the **Reality Gem**, which gives the user total control of reality.

So far, we have seen 4 of these stones in the MCU, in varying forms. 

Very mild spoilers for The Avengers/Avengers Assemble, Thor: The Dark World and Guardians of the Galaxy below.

>!<ul><li>In *The Avengers/Avengers Assemble* we see the Tesseract is the Space Gem and that Loki's Staff contains what could soon turn out to be either the Mind Gem or the Soul Gem.</li><li>*In Thor: The Dark World* we see that the Aether is one of the Infinity Stones</li><li>In *Guardians of the Galaxy* we see that the mysterious orb contains one of the Infinity Stones.</li></ul> However, both the Purple Infinity Gem seen in *Guardians of the Galaxy* and the Aether in *Thor: The Dark World* appear to fulfill the role of the Power Gem. 

So my question is - **which of these items in the films match the Gem in question, and what is the function of the other?**