Naanabrak is a rare and much sought after resource. It is generally described as black stone that radiates an eerie purple glow when under the aura of Leptyr.
Naanabrak radiates a permanent anti-magic shell in a 5' radius. This makes psionics and magic useless in its area of effect. One of the most well-known building that was constructed of naanabrak is XI Institute. It was used in this building to keep those who used magic from finding a way in.
One of the largest structures using naanabrak is the wall Oratu Iru. Bands of naanabrak were used as the wall's outer facing plates; making Oratu Iru impervious to magical attacks from that direction.
Barhaz Halarax is another place with an abundant supply of loose naanabrak. Since this ruin is quite dangerous, few scavengers have made it in and out with more than a half-full.
Try fighting a vampire or demon in an area of naanabrak. You will find that breaking torches and using them as stakes is your only salvation.
- Ryglaglanis, former member of Black Banner - "Good as Dead"