Nox Crystal

Nox Crystals are a reagent used by the magic school of Necromancy in Ultima Online.

Ultima Online
Only very little is known about these mysterious, green crystals that act as a reagent. It is known that that they can't be mined by ordinary people, only bought from specialists. In spells, they add a comonent of poison and/or malice.

Trivia

 * These crystals can only be bought from special shops, or found on slain monsters.