Warpstone is a fictional mutagen found in the Warhammer world, and also in the Warhammer 40,000 universe during the first and second editions. Humans and most other races in Games Workshop’s campaign game Mordheim refer to it as Wyrdstone.
Warpstone is solidified Dark magic (Chaos Energy, aethyr), and as such it holds tremendous transmutatory and alchemical powers. In its unrefined form, it is a stone that emits “blackness”, appearing to swallow all light from its surroundings, and so creates a patch of darkness around itself that makes it impossible to see its exact shape. It is sometimes described as “still emitting its own green glow”, which would result in a rather complex optical illusion. Everyone in the vicinity of a lump of unrefined Warpstone for more than a few hours is in danger of gaining a mutation. Refined Warpstone is considerably less dangerous. It takes the form of translucent crystals or a grey powder that must be ingested (or otherwise enter the body) to even get a chance of causing any mutations. Its long-term effects, though, seem to be similar to those of some psychoactive drugs.
Judging by the statements in the history of some races (such as the Lizardmen), warpstone was most likely created by the collapse of the polar warpgates created by the Old Ones; pieces of warpstone are most likely to be the remaining fragments of the gates after Chaos entered the world (the fact that Chaos entered the world with the collapse of the polar gates might indicate the origin of warpstone's mutagenic properties).
During the time period detailed in the Mordheim game, Warpstone is discovered to be the catalyst in a working philosopher's stone: Warpstone can be used to turn base metal into gold. After being devastated by a comet made of the stuff, Mordheim is quickly besieged by adventuring gangs hoping to strike it rich. After Emperor Magnus the Pious ascends the throne, it is discovered that Wyrdstone, once believed to have all manner of beneficial properties, is actually a creation of Chaos, and so its use is outlawed. The recipe for the transmutatory elixir has been forgotten, though some still attempt to rediscover it, and now it is mostly wizards who have any dealings with this substance, as it is a key ingredient in many magical spells.
Warpstone is extensively used by the followers of chaos, the skaven and the undead
Warpstone has a special tie to the Skaven who use it as fuel and regard it as sacred. Unknowing human scholars often class them as Beastmen, who are a degeneration of man, but Skaven are rather an evolution of rat, created by exposing ordinary rats to Warpstone.
Warpstone is used extensively by the Skaven, and Warptokens are generally recognized as their major form of currency (and sometimes sustenance) but each clan utilizes it in a different way. Perhaps the most recognized use is that of Clan Moulder, to mutate creatures into unnatural forms for their diabolical purposes by dissolving it into a paste that can ‘glue’ disparate body parts together. Clan Skryre uses the magic-infused stone to run huge war engines and strange inventions out of a mad scientist’s worst nightmare. The Clans Pestilens and Eshin use it for slightly more mundane purposes, to increase the potency of their poisons and toxic brews.
Some Skaven, such as Grey Seer Thanquol, use Warpstone as a narcotic in a similar manner to snuff.
The undead (see Vampire Counts and Tomb Kings) also use warpstone extensively. It was used by Nagash in his early life preserving elixirs along with human blood, and it is from these elixirs that vampires were eventually created. It was also used by Nagash in his first experiments at animating corpses. His fortress was built atop a mountain rich in warpstone. Here he employed his undead workers in mining it. This warpstone also attracted Skaven and started a tradition of warfare between the two races over the magical substance.
Corpse Carts in the Vampire Counts army make use of bells with clappers composed of Warpstone or magical flames, called Balefire, fed with warpstone powder.
- Chaos Emeralds are mystical items of various colors (appearing in the Sonic the Hedgehog series of video games) that also have certain transmutational powers.
- Magestone from the Mage Knight miniature wargame is a magically-infused mineral that, in unprocessed form, produces highly dangerous radiation.
- Materia are small balls of crystallized Mako energy (the ‘substance’ of Gaea) used in the magic system of the role-playing video game Final Fantasy VII. They have some mutagenic properties and allow the user to cast various magic spells and use special abilities.
- H. P. Lovecraft’s colours out of space are mutagenic non-humanoid alien creatures that arrived in a meteor with odd properties.
- Phazon, from the Metroid Prime video game series, is a mutagenic mineral that possesses “life-like qualities”.
- Tiberium, from the Command & Conquer video game series, is a green/blue plant/crystal that bears mutagenic properties.
- Lyrium, from the Dragon Age franchise, is a magical substance used to enchant items, allow mages to travel to the Fade, and can also be prepared as a potion to restore a mage's mana points.
The maban (magical essence) of Australian Aboriginal mythology is by some tribes identified with tektites, black or olive-green natural glass objects that most scientists believe to have been formed by the impact of large meteorites on Earth’s surface.
The black sword Stormbringer also is of chaotic origin and is sometimes described as radiating blackness.