What material are Infinity Stones made of?

Question

As for the MCU, the story goes (explained in full in an exposition-heavy scene in Guardians of the Galaxy) that six entities existed before the universe even came into being (try getting your head around that one) and, after The Big Bang, the entities transformed into the six Infinity Stones, one for every fundamental aspect of the universe. Okay, slightly less weird, but still fantastically silly. (Source)

I'm wondering what material are Infinity Stones made of. Was that ever mentioned in comics?

Answer 1

The closest we have are some quotes from Infinity War: Vision describes the Mind Stone to some extent:

Vision: No, we have to destroy it. I've been giving a good deal of thought to this entity in my head, about its nature. But also, its composition. I think if it were exposed to a sufficiently powerful energy source, something, very similar to its own signature, perhaps… Its molecular integrity could fail.

Later, when Vision is taken to Wakanda, and Shuri scans the stone for potential removal:

[In Shuri's lab, Shuri scans the Stone with her kimoyo beads while Vision lies on the examination table. She flips her hand over and studies the hologram projected over her palm]

Shuri: Whoa. The structure is polymorphic.

While these two instances don't tell us exactly what the stones are made of, it is safe to say they are indeed made of "polymorphic" regular matter, made up of molecules of some sort.

Answer 2

We don't know

In Guardians of the Galaxy The Collector just states they are singularities that were forged into concentrated ingots. Whatever that means.

The Collector: Oh, my new friends. Before creation itself, there were six singularities. Then the universe exploded into existence, and the remnants of these systems were forged into concentrated ingots. Infinity Stones. These stones, it seems, can only be brandished by beings of extraordinary strength.

_{Guardians of the Galaxy}

However, in Avengers: Infinity War Wong states they are elemental crystals.

Wong: From the dawn of the universe, there was nothing. Then, boom! The Big Bang sent six elemental crystals, hurtling across the virgin universe. These Infinity Stones each control an essential aspect of existence.

Doctor Strange: Space. Reality. Power. Soul. Mind. And Time.

_{Avengers: Infinity War}

That is about as much information we have on what they are so we don't really get any information on what they are made out of.

Answer 3

The Stones are made of atoms.

In Endgame, we have this dialog

STEVE ROGERS : Where are they?
...

THANOS : The universe required correction. After that, the stones served no purpose, beyond temptation.
...

NATASHA ROMANONFF : Where are the stones?

THANOS : Gone. Reduced to atoms.
...

THANOS : I used the stones to destroy the stones. It nearly... killed me. But the work is done. it always will be. I am inevitable.

I'm fairly certain this is meant to work around the inevitable nitpicky question of whether it makes sense that the Stone are powerful enough to destroy themselves: They weren't destroyed. They were just dispersed around to the point they can't be reassembled so can never be used again.

At any rate-- there you have it. They are made of normal atomic matter.

Answer 4

In the comic Thanos Quest #2, we learn that the Collector has subjected his gem (the Reality Stone) to considerable scientific study. Although he was unable to detect the underlying power that the stone represents, he was able to ascertain what material it's comprised of. Nothing more than "a worthless hunk of polished glass".