Petricite Trees are fossilized-like trees that were magically altered by World Runes. They have magic-dampening abilities as well as the ability to absorb magic. Several stories high, these white trees and their yellow leaves are as hard as stone. The early settlers of Demacia discovered a petrified forest that can dispel magic, and mixed this wood with ash and lime into the resistant material that is called Petricite. From this innovation, the walls of Demacia were established. The material used by Demacians in defensive walls, military, and public security. It is also used in Demacian architecture due to its white and elegant appearance. However, they are a limited resources as the trees have stopped growing at the moment. The name of these trees was likely just derived from "petrification", which literally means something organic turned into stone, or becoming stone-like, and the suffix -cite comes from Greek.
Petricite can be ground up and mixed with liquid to make Petricite Elixir. The Mageseekers have the more powerful mages that are imprisoned beneath their headquarters ingest the elixir to nullify and contain their magic.
- The general rumor in Demacia is that petricite elixir causes "bouts of excruciating pain". 
believed that it would also probably taste bitter.
- Several years later, Lux witnessed an imprisoned mage being given some elixir, and later drank some herself on purpose. Ingesting it does appear to at least be unpleasant, and while having it enter ones stomach seems to be painful, Lux quickly recovered from it.
- By putting petricite inside the digestive tract, the material would be in direct contact with the mage and absorb their magic from within. However this also means that, as what goes in must come out, the petricite would inevitably be passed out of the system in a day or so, making this method temporary at best.