Fire agate

Fire agate was a form of chalcedony which contained goethite arranged in thin lines, giving this stone an iridescent quality.

Description
These ornamental stones came in red, brown, gold, and green varieties and in the finest specimens the chalcedony was partially translucent, allowing the color to come through. A typical stone had a base value of 10 gp.

Appearances

 * Icewind Dale