Thuparlial

Thuparlial, also known as prehnite, was found in hardened lava as a lining to gas cavities in the rock, but rarely was this lining thick enough or an attractive color to warrant cutting it into gemstones.

Description
Thuparlial was hard, resilient, and translucent gemstone which varied in color from deep green through pale greenish yellow and from yellow to brown. Thuparlial was cut in facets if light-colored but otherwise made into cabochons. It was considered an ornamental stone and a typical specimen had a base value of 10 gp.

Powers
Powdered, this mineral was used in inks for creating the pyrotechnics and heat metal spells. Red wizards who had access to large quantities of thuparlial experimented with using it as a substitute ingredient for many fire- and heat-based spells. It was unknown if they succeeded.