Originally Posted by Rock Sexton
As you pointed out Loki was able to shroud what he was doing in Johunteim from Heimdall. If Loki were to have snatched the mind gem off the IG in "Thor" in order to do that, we would've been shown it. However, the only artifact in the vault they showed Loki stage any interest in was the Casket.
You're also assuming Loki even knew what the IG and gems were in the first place. We could attempt to suggest that since Odin was telling he and Thor the story of the casket in the opening of "Thor", there was potential for that with the other stolen relics. So if he knew the backstory of the IG/gems, why would he not take them all given the importance/power we all assume it to behold?
If Loki were to have bargained the gem for the cube we would have been shown that. What were were explicitly told at the beginning of Avengers was Loki bargain the the cube for Earth.
Yes you might have forgotten this but remember my theory that had to with Whedon drastically rewriting the Avengers script? Thanos was never planned until Whedon rewrote the script, the IG was therefore not of relevance when they shot the Thor 1 movie.
Ofc Loki knows of the IG. He was raised as a son by the Allfather in Asgard. Itīs also Loki we are talking about here. Itīs not strange to make Loki know of the IG without earlier introducton of him learning it.
Why not take the IG given its power/importance? An excellent question ofc. I must admit, I canīt see any reason for why he shouldnīt have taken more gems or the entire gauntlet. If you had to guess on this Rock, what would you think?
Would we have been show that? I donīt think so. The Chitauri had big plans using the cube so that they could acess new worlds. Loki would get Midgard. So let me ask you, what would Thanos get?
I see it like this. Loki can offer the gem to Thanos. Chitauri can invade Midgard and give Loki the planet. Chitauri can offer tech to get there via the cube. But why would they give Loki tech and help him take the planet? Loki knew of the cube and it was not of importance for him, he wanted to rule.
Basically Loki can offer Thanos the gem if Thanos can offer Chitauri the cube if they offer him a scepter which will allow Loki to take Midgard and therefore forfill giving Thanos his gem.