Linrock

Linrock (リン) is a mineral found in Tortus.

Description
Linrock is a pale blue stone that glows upon coming in contact with the air.

It was used as a material for Miledi Reisen's Great Labyrinth.

Trivia

 * Linrock is based on the real life element, which has been known to glow when exposed to oxygen. It is also based on the fictional element "Aetherium" from the movie Castle in the Sky.
 * In the Anime, the glowing rocks in Miledi's Labyrinth emit a yellowish glow.