Corstal

Corstal, also infrequently known as petalite, was a rare mineral and especially hard to find without impurities. They were worn by nomadic tribes and those that could not afford better jewelry.

Description
These ornamental stones were fairly hard but brittle and ranged in hue from colorless to pink. The rare stone that was free of impurities could be faceted, but otherwise these stones were cut cabochon. A typical stone had a base value of 10 gp.

Powers
Corstal crystals could become light sources for a short time by exposing them to magically generated radiance. Any source of light from fairie fire to flame strike that touched a corstal gem was mimicked in the heart of the crystal as it glowed with the same hue and intensity for a few minutes before fading away suddenly. The longest duration of this mirroring behavior ever observed was twenty-four minutes.