Steve Rogers: New haircut?
Thor: Looks like you've copied my beard.
Peter Quill: I'm gonna blow that nutsack of a chin right off your face.
Thanos: I know what it's like to lose. To feel so desperately that you're right, but to fail, nonetheless. It's frightening. Turns the legs to jelly. But I ask you, to what end? Dread it, run from it, destiny arrives all the same. And now, it's here. Or should I say, I am.
Nick Fury: Motherf...
Bruce Banner: Hulk? Hulk? I know you like making your entrance at the last second. Well, this it it, man. This is the last, last second. Hulk! Hulk! Hulk!
Hulk: No!
Bruce Banner: Oh, screw you, you big, green asshole! I'll do it myself.
[Thor arrives in Wakanda.]
Bruce Banner: Ha-ha! You guys are so screwed now.
Steve Rogers: Drop to 2600, heading 0-3-0.
Sam Wilson: I hope you're right about this. Or we're gonna land a lot faster than you want to.
Peter Quill: Tell me where the girl is or I swear to you I'm gonna French fry this little freak.
Tony Stark: Let's do it. You shoot my guy and I'll blast him. Let's go.
Drax: Do it, Quill! I can take it.
Mantis: No, he can't take it.
Doctor Strange: She's right. You can't.
Peter Quill: Groot, put that thing away, now. I don't want to tell you again. Groot.
Groot: I am Groot.
Peter Quill: Whoa.
Rocket: Language.
Gamora: Hey.
Drax: Wow.
Peter Quill: You got some acorns on you, kid.
Rocket: Ever since you got a little sap, you're a total d-hole.
Bus Driver: What's the matter with you kids? You've never seen a spaceship before?
Dr. Stephen Strange: What master do you serve?
Peter Quill: Oh, what master do I serve? What am I supposed to say, Jesus?
Tony Stark: You can't park here, buddy. Earth is closed today. Take your tractor beam and skedaddle.
Eitri: You're about to take the full power of a star. It will kill you.
Thor: Only if I die.
Eitri: That's what...killing you means.
Doctor Strange: I went forward in time to view alternate futures. To see all the possible outcomes of the coming conflict.
Peter Quill: How many did you see?
Doctor Strange: 14,000,605.
Tony Stark: How many did we win?
Doctor Strange: One.
Rocket Raccoon: How much for the gun?
Bucky Barnes: It's not for sale.
Rocket Raccoon: How much for the arm? [Buck walks off.] Oh, I'm gonna get that arm.
Peter Parker: I need you to create a distraction.
Ned: We're all gonna die!
Thor: The rabbit is correct, and clearly the smartest among you.
Rocket: Rabbit?
T'Challa: Wakanda forever!
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