Nirncrux, commonly called red brittle, shake stone or miner's bane, is a red stone found only in Craglorn. In its raw form, it releases a poisonous gas when cracked which can cause symptoms ranging from nausea, body tremors, and disorientation to convulsions, slurred speech, memory loss and death. One theory on why Nirncrux is abundant in Craglorn is that the Nedes of the area used arcane rituals to draw it from deep in within Nirn's crust. Regardless of the validity of this speculation, the Nedes learnt how to harness its ability to absorb and distribute Aetherial energy.
Nirncrux is found naturally in a solid form, as veins running through denser rock throughout the upper region of Craglorn, and sometimes as grains and nuggets along river beds and at the base of hills and mountains. In this form, it is brittle and flaky, resists most acids, and does not tarnish when exposed to air or water. However, it is not dense enough or strong enough in this form to create weapons or armor.
When crushed into a powder or dust, the Aetherial energy can be released from each grain of dust using an ancient Nedic ritual which can be used in potions and elixirs. The Iron Orcs utilized crushed nirncrux in ink to create power-enhancing runes right into the flesh of trolls and welwa, they also used nirncrux in the armor worn by these creatures, as it boosted the toughness and power of the armor. When the runes and armor were combined, it caused the creatures to become infused with pure nirncrux, resulting in great power. They also washed the trolls in nirncrux-infused mud. The Scaled Court also used this form of nirncrux to create the Mantikora in spawning pools by mixing in nirncrux.
The Reachmen Dreadhorn Clan used the Bloodroot Forge, an ancient Nedic forge in the Jerall Mountains, to turn themselves into the Blood-Forged. These abominations are comparable to Briarhearts, but their creation involves implanting a nirncrux heartstone instead of a briar heart, resulting in a being that is an amalgamation of blood, nirncrux, and iron. Their shamans also painted symbols using nirncrux powder and blood.
Nirncrux heartstones are comparable to the heartstones that have rained from Red Mountain since the cataclysmic events of the Red Year. Like the creation of a Briarheart, and by extension a Blood-Forged, a substitute is used in the place of a mortal's heart (in this case the heartstone), leading to the resurrection of the subject.
Nirncrux is so prized by the miners of Craglorn that it is conveyed in special bowls.
- Ahmih's dialogue
- Timmon Junciennes' dialogue
- Nirncrux: A Study — Mendan Flot,
Regent of Roiling Concoctions
- Little Leaf's dialogue in ESO
- The Care and Feeding of Trolls — Gulzog the Butcher
- It Lives! — Boward, Regent of Wriggling Nightmares
- Filand's dialogue in ESO
- Blood-Forged skin description in ESO
- Dreadhorn Shaman skin description in ESO
- Neloth's dialogue in Dragonborn.
- Ildari's Journal, vol. I — Ildari Sarothril
- Nirncrux bowl description in ESO
- Rena Hammerhands's dialogue in ESO