Chrysoprase

Chrysoprase was a semi-precious stone found all across the Realms. The largest deposits were located in the Storm Horn Mountains of Cormyr were it was known as stormrock.

Description
Chrysophrase was a translucent form of chalcedony that had a color reminiscent of green apples. It was a popular gemstone in Cormyr where it often found use in women's earrings and brooches worn on the chest. A typical stone had a base value of 50 gp.

Powers
Chrysoprase was used in the creation of items and spells that dealt with conferring or piercing invisibility effects. It could be ground to a powder and used in magical ink for inscribing scrolls with invisibility or anti-invisibility spells. It could be used as a spell component in those same spells, and it was often used to adorn rings of invisibility.

Chrysoprase was one of the "nine secrets"&mdash;stones that could be enchanted to become ioun stones.