In some of the universes featured in my works, a material known as Skarilium exists. This material is used by humanity, in a universe where we’ve successfully colonized the majority of Mars and are in the process of colonizing other planets in the solar system, as armor plating on fighter jets that double as spacecraft.

Skarilium has the following qualities:

  • It is lightweight, weighing roughly 3150 kilograms per cubic meter
  • It is extremely enduring, being able to withstand the conditions of the Upper Mantle of Earth for up to 30 minutes with only minimal burns, even if in the form of a sheet that’s 2 millimeters thick.

Now with those qualities, what are some environments where Skarilium could potentially occur naturally? Furthermore, depending on the nature of those environments, would it be something that humans could potentially have the technology to obtain by 2062?

P.s. I’ve been informed that the above example of how lightweight Skarilium is would make it lighter than Earth’s Air is at sea level. I did not intend for it to be lighter than air. For better reference, it is meant to be more lightweight than the lightest metal in real life, but is not as lightweight as air.

P.s.s. I’ve changed the qualities of Skarilium somewhat.

P.s.s.s. I’ve changed the qualities of Skarilium again.

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    $\begingroup$ In our universe no such chemical element exists. In the fictional universe where such an element exists, it will of course occur in exactly those environments where the plot requires it to occur; and the fictional hyoomens may or may not have the technology to obtain it by the year that they count as MM.LX.II, also depending on the plot of the story. (Note that the hyoomens of the fictional universe are very obviously very unlike the humans of this universe, given that the two universes are completely different with totally different physics and chemistry.) $\endgroup$
    – AlexP
    Sep 9 at 22:07
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    $\begingroup$ @AngryMuppet: It is less then half the density of Earth air (1953 cubic meters of air would weigh about 2.3 tonnes.) But we don't know the density of the air in the fictional world where such a chemical element exists. $\endgroup$
    – AlexP
    Sep 9 at 22:11
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    $\begingroup$ That is an astonishing coincidence, given that in the fictional universe physics is so very different from ours... $\endgroup$
    – AlexP
    Sep 9 at 22:23
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    $\begingroup$ Also, because @AlexP is being oblique about it, stating it outright - in real life, Skarilium wouldn't "probably" not be an element. It cannot be an element, as there is no room for an element with those properties on the Periodic Table. (And you can't have an element "8.5" or any such thing in our universe.) This is why AlexP is insistent that this is a radically different universe, because how its elements operate would have to be very, very different. $\endgroup$
    – jdunlop
    Sep 9 at 23:29
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    $\begingroup$ (This would necessarily radically change physics, chemistry, and practically everything else, in ways that are probably difficult to work out consistently. So Skarilium may as well be magic.) $\endgroup$
    – jdunlop
    Sep 9 at 23:30

3 Answers 3


No, it's impossible.

The material is lighter than air.

This is a fairly impressive feat for a solid substance. You haven't changed the volume and weight, so I assume this still stands.

It's stronger than the strongest substance on earth.

It's more heat resistance than the toughest substance on earth, Tantalum hafnium carbide alloy, which has a melting point of 3990C. The outer core is 4500C plus, so this material is very heat resistant.

If you want the material, it would have to be some sort of magical sci fi material with impossible properties. You could have it be the result of some alien experiments with altered physical laws, say.

  • $\begingroup$ I haven’t changed the volume and weight because I don’t know what to change it to, to be honest. As for the other side of this, I knew that it had extremely high heat resistance, that’s part of the point of coming up with this material. $\endgroup$ Sep 9 at 22:59
  • $\begingroup$ Since it is massively beyond earth materials I wouldn't expect there to be a normal physics answer- it would just have to be a sci fi mineral with impossible properties. You can then give it any properties you want. $\endgroup$
    – Nepene Nep
    Sep 9 at 23:01
  • $\begingroup$ @NeptuneNep That’s true too, to be honest. $\endgroup$ Sep 9 at 23:03
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    $\begingroup$ (Though I would again stress that if you claim it to be an actual element and suggest that the world is very like ours, you will thoroughly break suspension of disbelief for a subset of your readers.) $\endgroup$
    – jdunlop
    Sep 9 at 23:40
  • $\begingroup$ There are a lot of stories which have impossible elements in them with super powers. It wouldn't be the first time. $\endgroup$
    – Nepene Nep
    Sep 10 at 12:47


Your colonists harvest diamonds from the diamond layer on Uranus and Neptune.

diamond layer


Very large chunks are obtained and processed into the desired shapes. The processing method is owned by Skarilco and modifies the diamond into Skarilium™. The exact method is a trade secret but involves doping the native diamond with boron and other elements.

Skarilium™ is not lighter than air. It is not lighter than aluminum either. It is however extremely durable and conditions in the Outer Core of Earth are not stressful for either diamond or Skarilium™.

  • $\begingroup$ Interesting answer, to be honest. Love the idea, too. The one problem I have with using this idea in any capacity is that it doesn’t naturally occur as Skarilium. It naturally occurs as Diamond. However, given how little I’ve worked on Skarilium, I can definitely get around that. $\endgroup$ Sep 9 at 22:54
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    $\begingroup$ Diamonds are extremely flammable and easy to burn with even a normal flame, quickly puffing away into carbon dioxide. $\endgroup$
    – Nepene Nep
    Sep 9 at 22:56
  • $\begingroup$ To be honest, I did not know that about Diamonds. Maybe this answer isn’t as plausible of a solution. $\endgroup$ Sep 9 at 23:00
  • $\begingroup$ Also, a thin sheet of diamond is both brittle and flammable. Probably doesn't fit the bill. $\endgroup$
    – jdunlop
    Sep 9 at 23:36
  • $\begingroup$ @jdunlop - how do brittle and flammable violate the OP? I gave up on the lighter than air but diamonds do fine in crushing pressure and great heat. There is no free oxygen in the mantle so nothing burns. $\endgroup$
    – Willk
    Sep 10 at 1:13

With your new requirements, something like an Al-Ti-Cr alloy may come close to satisfying your needs.

The exact density depends on the precise composition, however with Aluminium at about 2700kg/m³, a density of 3150 seems believable.

The outer mantle has temperatures in the range 300-1000 celsius. And these alloys can maintain strength up to about 800 celsius. Now although they can retain strength, the rocks in the mantle are under considerable stress, You won't be able to make a chamber in the mantle. Nothing can withstand the force of 100km of rock crushing it. And even if these alloys can maintain strength, they still conduct heat. Again, you won't be able to make a tunnelling "Mole machine", or a supervillain underground base!

These alloys won't occur naturally, they will be produced in the lab (or factory) the specific properties are not just dependent on the composition, but the treatment of the metal as it is heated and cooled, rolled and worked.


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