Orbaline

Orbaline was the common name in the Realms for benitoite.

Description
Orbaline crystals were relatively soft and usually found in fragments rather than whole crystals. The most common use for orbaline was as an inlay for coffers, ornamental boxes, and statuettes. When a specimen was large enough to cut, these yielded blue to colorless faceted gems. . A typical specimen had a base value of 500 gp.

Powers
Orbaline, when inlaid or mounted on an object, greatly increased that object's resistance to magical fire and conferred almost as much benefit against normal fire. This only affected inanimate objects; living creatures and undead could not gain this boon.