Why would Tony hold the Infinity Stones?

Because the “Iron Gauntlet” that Thanos was wearing is made of the same nanotech as Tony Armor, Iron Man was able to simple manipulate the nanobytes in both gauntlets to shift the Infinity Stones over to his hand, instead of Thanos’.

Why is Wanda the only one who can destroy the stone?

According to Vision, Wanda was able to destroy the Mind Stone because her powers operate on a “very similar… signature” to the Infinity Stone. Her powers possess a similar signature to the Infinity Stone because her own Chaos Magic has been bound to it in some way.

Who can wield the Infinity Stones in the comics?

In the Guardians of the Galaxy movie it is stressed that a mortal human cannot wield the Infinity Stones. In the comics, however, several humans appear to have wielded one or more Infinity Gems including The Hood, Iron Man, Dr. Strange, Mr. Fantastic, Beast, and Charles Xavier.

How did the Infinity Gauntlet shatter the gems?

When Captain America used the Infinity Gauntlet to move a planet the strain caused the gems to shatter. The others who have held the Infinity Gauntlet – Thanos, Nebula and Adam Warlock were all super powered and able to use it without destroying the gems.

Could a normal human wield an Infinity Gem?

The premise that a normal human could not effectively wield an Infinity Gem is not unique to the Marvel Cinematic Universe. While the MCU shows the gems having catastrophic effects on anyone unfamiliar with the gem, it was possible for beings of immense power such as, Ronan the Accuser, to use the power of the purple Infinity Gem without dying.

Do the Infinity Gems have sentience?

When we see the Infinity Gems in the canon Marvel Universe, they never showed up in the hands of people who don’t already possess superhuman power. It is almost a requirement to have superhuman abilities to find them or use them. It can be said the gems possess a kind of sentience as well and allow their use if it suits their purposes.