Trivia: Spoiler! Whilst Groot is turning to dust after Thanos activates the complete Infinity Gauntlet, he says "I am Groot" to Rocket just before he dies. James Gunn, writer/director of the Guardians of the Galaxy movies, confirmed via Twitter that Groot was actually saying "Dad" to Rocket before dying. (02:13:45)
Trivia: On Knowhere, Thanos is questioning The Collector, played by Benicio Del Toro, for the location of the Reality Stone. He asks him "Where is the stone?" at one point. This is a reference to a heist scene from the movie Snatch, in which Benicio Del Toro is robbing a bank and asks "Where is the stone?" with the same line intonation. (00:48:45)
Trivia: When Star-Lord attempts to shoot Gamora with his blaster before she is taken by Thanos, Thanos uses the Reality Stone to turn his blaster into bubbles. He also later does this when Gamora attempts to stab herself. This is a reference to the fighting game Marvel vs. Capcom 2: New Age of Heroes, where attacks by Thanos often involved the use of bubbles. (00:53:30)
Answer: "Doctor Strange" demonstrates that the Infinity Stones are useful in the most dire of situations, when Strange used the Time Stone to prevent Dormammu from taking over the Earth. It's also possible that some of the stones are indestructible. Wanda is able to temporarily destroy the Mind Stone by using her own powers, but the Power Stone will destroy any being that doesn't possess the strength to wield it, and the Reality Stone is shown to have a will of its own and defended itself when it bonded with Jane Foster.
Phaneron ★
Also, in the comics, if the stones are destroyed they will simply be replaced by something else or even stones again. They represent the existence of the universe and cannot be destroyed for real. Always only temporarily.
lionhead