Mellochrysos

Mellochrysos was a variety of zircon found in large crystals in the Realms.

Description
These semi-precious stones were an intense yellow hue and very resistant to chipping in natural form. As such, they were seldom cut, but rather polished and mounted in metal claw settings, typically for rings, brooches, and knife hilts. A typical specimen had a base value of 50 gp.

Powers
Mellochrysos crystals had an unusual property after being the target of a light spell: within one day of being a magical light source, the crystal could be briefly held in an open flame and would ignite, giving off a single flame like a candle. The stone would fuel this flame, being consumed very slowly, for up to 12 hours. The flame could not be extinguished by wind or water, even magically generated air or water effects, but spells such as quench fire and the property of phenalope were effective. The mellochrysos flame was hot enough to ignite flammable materials.