"The problem with adamantium is that once you've processed its raw, liquid form—you've got to keep it that way. You've got to keep it hot. Because once it cools...its indestructible."
"It is so durable that it never degrades, testing the patience of Time itself. Traditional weapons are useless against it; it is easier to put dents in the laws of physics than in its surface. ... It's easier to make tiny changes to reality than it is to change darksteel. You change the fact of its shape rather than alter the metal itself."
"Well it'll take a lot longer to get through the blast door," said Captain Proton. "It's made of neutronium, the hardest substance in the universe. Mined from the heart of a collapsed star in violation of all scientific plausibility."
"OK wiseguy, if neutronium's the hardest substance in the universe, how were they able to slice it up into door-shaped bits?"
— Plan 7 of 9 from Outer Space