Deadiron

The people of Yronroost are well acquainted with the stuff, so much so that they're probably the only people across the cosmos that can handle the material in its raw form for more than a few seconds without suffering from the effects of exposure. But they say that you haven't ever seen suffering until you've buried a living being in deadiron dust or put them in a deadiron cage. And as much as I hate to admit it, having seen people flayed alive with a single look by some of the nastier creatures of this damnable place, screaming for hours in agony before finally dying from the sheer shock of it all, they might just be right.
It's pretty common knowledge that iron kills arcane magic in our world. I don't know the science behind it all, I only know the facts, but I think it has something to do with iron absorbing arcane energy and turning it into waste heat. Whatever that means. But deadiron, which has a name far more awesome than its properties, kills any and all kinds of magic except for blood magic, and even that doesn't always work the right way around the stuff. But more than that, raw deadiron practically kills anything and everything that it touches. I don't know how and why, and I'm sure there are a hundred other smarter people than me working on figuring that out, but I think it has something to do with the way that even holding a forged deadiron weapon, I can still feel it leaching not just the heat, but the energy and life out of me.

— Clariyen, of the Order of the Mistwalkers
Speaking to a colleague about deadiron

Deadiron is a strange material in the world of Rivendom. It does not occur naturally in the Material Realm, at least as far as science has been able to determine, and most experts agree that it is highly improbably that any such substance exists anywhere in the material realm. However, Deadiron, also known as terminium and relictite, can be found in enormous spherical deposits floating about in the Shardscape, These spheres are known to glide slowly through the ever-twisting landscape of the Shardscape, causing calamity wherever they appear.
The Shardscape realm of Yronroost is in fact a ring city built around one of these large spherical deposits. The origin of the city itself or its original inhabitants, known only as the Architects, is unknown, only that it is one of the few mobile realms within the Shardscape, moving with its home deposit across the tumultuous wilds. The inhabitants of Yronroost are among the few people in the entirety of the Rivendom multiverse who can tolerate direct exposure to deadiron for more than a few seconds, and being in the presence of raw deadiron for more than an hour or so.

Properties

Material Characteristics

Deadiron looks very much like the element that it is named after. It is distinctly metallic in appearance and demonstrates all of the aesthetic properties of elemental iron. The major difference between deadiron and elemental iron is in the colour. Whereas elemental iron is silvery in hue and has a brilliant lustre, deadiron is a deep almost-black silvery hue with only a very subtle lustre that is most highlighted when it is in its dust form. Deadiron has at times been said to "drink in the light that touches it, making the world darker by virtue of its presence alone."

Physical & Chemical Properties

Deadiron appears to have a metaphysical property that allows it to absorb and dispose of vast amounts of energy. The mechanism by which the material accomplishes this is unknown, but metacosmologists believe that the energy is being directed elsewhere, to a regime of the multiverse which is completely inaccessible from anywhere else within the multiverse and even without it.
Trueborn Knowledge

Those that have the means to do so have consulted with the Epherim, and have managed to find out that the trueborn gods are well aware of the properties but are inexplicably unwilling to talk about the matter. When asked as to whether doing so would be a contravention of their vow of nonintervention, those who elected to dignify the question with a response said that it was more a violation of what should have been fundamental aspects of the multiverse.
The most information that has been received so far on the topic comes from the Stranger, via one of his clerics. The god, reportedly, emphatically stated that deadiron was never meant to exist in the world of the living. When asked to clarify which beings he referred to by "the living," given that the definition is known to change from one universe to the next, it is said that the Stranger simply stated: "everything."

One of the most notable features of deadiron is the intense temperature that is needed to properly forge even a small amount to shape, requiring temperatures approaching the conditions that can be found at the core of average main-sequence stars like the sun. Each heat of a bar of deadiron stock can take almost a month at well over 15 million Kelvin, which is thought to be the amount of time it takes to saturate the energy wicking capabilities of deadiron, placing it in a state where it begins to act much more like elemental iron.
However, the most well-known property of deadiron comes from its raw form, where it seems to suck the energy out of everything that it touches. Springs and simple harmonic oscillators with deadiron weights attached consistently experience a significant damping effect even in a perfect vacuum in a weightless environment. Flames that are exposed suddenly to deadiron are consistently colder than they should be, and in fact, even a small handful of deadiron dust is able to completely kill a flame, not by smothering it, but by outright consuming all of the energy produced by the combustion reaction before it can create a plasma.

Chemical & Physical Analyses

Scientific analysis of the material shows no discernible chemical or physical differences between energy-saturated deadiron and elemental iron. Multiple studies have found conclusive evidence that physically and chemically that energy-saturated deadiron is effectively indistinguishable from elemental iron at comparable temperatures. In fact, one of the more puzzling observations brought about by a cursory examination of the material is that deadiron is more unreactive than noble gases at room temperature, going so far as to refuse forming protective oxide layers like other metals. This is both useful and detrimental as blocks of deadiron can be cold welded at room temperature without a vacuum, but it also means that deadiron dust tends to clump together and destroy delicate machinery.
Magical divination proves entirely ineffective at the material's ground state but also reveals no discernible chemical or physical differences between energy-saturated deadiron and elemental iron, only providing the faintest sense that there is a distinct difference between the two materials' metaphysical properties.

Exposure

Exposure to enough raw deadiron can be fatal as it sucks the energy right out of any given energetic system, including the metabolism of a living body. This happens most efficiently through contact, but even just exposure to airborne microparticles of deadiron has a negative impact on the health of unacclimated individuals. Chills, lethargy, and impaired cognition occur within minutes of exposure for the unaccustomed, and within seconds of physical contact.

Geology & Geography

Sporadic spherical deposits of deadiron are found hovering at various heights above the ground in the Shardscape. Each one can range from anywhere between seven and eight kilometres in radius. They are avoided at all costs by creatures native to the Shardscape and anyone who is aware of the nature of deadiron. Whereas small amounts of the material can suck the energy out of a living being in a matter of minutes, these enormous deposits leave a trail of devastation in their wake, killing off any static life wherever they pass. These deposits are so effective that they can suck the energy out of any creature standing within roughly 1 kilometre of their surface.

Origin & Source

The origin of deadiron is unknown but for a privileged few. Apart from one or two mortal creatures, only the Epherim truly know where deadiron comes from, and they are extremely secretive as to its origins. Mortals have managed to piece together clues as to the genesis of these objects, however, as it is widely known that they did not appear at the same time as the Shardscape manifested. With this knowledge, the living inhabitants of the multiverse are at least correctly aware that deadiron came from the material realm, which is paradoxical when considering the well-known fact that it does not exist in any of the known universes in the cosmos.
The True Origin of Deadiron

Deadiron is the byproduct of a dying universe. It does not exist in any known universe with life because it is only produced as the last dying throes of a universe. Deadiron is the result of an unimaginably long period of time passing in its home universe, long after the heat death of the universe, when all the stars have died, all life has long since disappeared, and even the largest of black holes have evaporated. Deadiron doesn't begin forming until an unimaginably long amount of time after the last white dwarf is reduced to a cold dead cinder in the great, enveloping cosmic dark.
At this time, the only real "events" that transpire are quantum mechanical in nature, with quantum tunnelling producing iron atoms at such a low pace that it will take practically an eternity before an entire star's worth of mass is converted entirely into iron. Before the genesis of the Shardscape, this was the end of it. However, with the creation of the Shardscape, over these vast periods of time, rifts into the Shardscape open in the dying universe. Without arcane magic to dampen their influence, as arcane energy streams from the hearts of stars, these rifts will simply get bigger and bigger, subsuming the entire universe into the Shardscape after an indeterminate amount of time, introducing more deadiron deposits into the Shardscape.
It is unclear how this happens, but it is during the transition of the iron stars into the Shardscape that they gain their metaphysical properties. In addition, during this transition, deadiron deposits undergo a strange transformation, losing the extreme density of their physical counterparts and instead becoming spheres of iron that would be unremarkable in terms of density or gravity if not for the strange metaphysical properties that they possess.

History & Usage

History

Despite its relative novelty with respect to the history of the world, deadiron has made something of an indelible mark on Sekhar. First brought there by Shardborn who came to the material realm either of their own volition or as a result of a spatial or temporal anomaly in the Shardscape, deadiron quickly became a material of interest, particularly to the tretalleri Dominion which is always looking for a means to get a leg up in the millennia-long conflict between them and the Silvered Realm of the elledŷnnë.
At first, it was hailed by researchers and generals alike as the key to breaking the tyranny of the elledŷnnë once and for all, as iron, steel, and star-steel were effective against the arcane arts but limited in terms of range as well as applications. When the energy damping effects of deadiron were first discovered by mortals on Sekhar, the hypotheses proliferated like maggots in a corpse. For instance, one of the easiest ways to get around protection against arcane magic was simply to chuck a bolder with significant force in the direction of one's target. It was theorized that with enough deadiron, a deadiron shield, for example, could possibly absorb all of the kinetic energy and render the magic ineffective in an entirely different way.

New Evidence

For a time, its merits were discussed in secret in the highest echelons of the Dominion, but as evidence rose about the effects of exposure to raw deadiron from the few that were brave enough to seek out a source for it in the Shardscape, the talks took on a different colour entirely. Generals went from figuring out ways to get deadiron weapons into their soldiers' hands to talking about whether it would be worth risking their lives for the sake of this supposedly-miraculous material. It was ultimately decided that deadiron was too dangerous to be used, despite its enormous advantages over normal iron, steel, and star-steel.
Even a proposition about deadiron arrowheads was tabled, the argument for doing so the fact that arrows are reusable. Even if the arrows would break through the opponent's magical barriers unimpeded, they could be fired back. Even if just a small amount survived being fired the first time, it would be undoubtedly catastrophic if they were used in retaliation. Not mentioned in that particular discussion was the fact that arrows with deadiron arrowheads flew for much shorter ranges than most other ammunition, anyway, the deadiron damping even the kinetic energy of the arrows that they're attached to.

Better Techniques

Sometime after the Dominion rejected the use of deadiron weaponry and munitions, the Architects of Yronroost were able to come up with their current process of forging deadiron. Earlier deadiron weaponry, which was made with inefficient techniques, ended up having more raw deadiron content in them than was necessary or healthy, but the decision had been made, and the Dominion does not retract its official statements without considerable debate. The market on the world of Sekhar had closed to deadiron, except for maybe the occasional buyer.

The Start of an Industry

But this did not spell the end for Yronroost's industry, as deadiron was very much sought after in the Shardscape, where a number of creatures are immune to most conventional types of energy, and deadiron, if it could not be used to destroy the creature, could at least be used to contain it. One of the biggest commissions that Yronroost ever received was from the Burdensome City of Gelethis, which wanted to replace the dark iron chains and shackles that bound the seven titans that dragged it across the surface of the icy lake that it lives upon.
Furthermore, soon after completing the contract with Gelethis, despite being a realm adjacent to the universe of Sekhar, Yronroost was contacted by beings from a different plane bordering an entirely different universe. This was the beginning of their partnership with Galbad and the acolytes of the Cult of Thruun whose psionic abilities allowed them to wield deadiron weapons more effectively than most other creatures by virtue of being able to keep the weapons at arm's length.
With deadiron proving to be a lucrative market, Yronroost marshalled its forces, buying the service of legions of warriors to fight on its behalf to protect its interests. Whenever another realm attempts to break into the market of deadiron, Yronroost stomps out the competition. With the only army in all the realms fully equipped with the highest quality deadiron, Yronroost is near-invincible on the field of battle, suffering defeat in none of their official engagements and only twice in all of their prearranged skirmishes with forces from around the Shardscape, most notably to the Order of Mistwalkers and to the Cult of Thruun.

²⁶Fe

55.845 u ± 0.002 u

Type

Elemental / Molecular

Odor

Odorless

Taste

Bitter & Cold

Color

Deep silvery-black with a faint lustre

Boiling / Condensation Point

Unknown

Melting / Freezing Point

Unknown

Density

7.874 g/cm3

Common State

Solid

About Iron Stars

From Kurzgesagt (In a Nutshell)