Eye agate

Eye agate was a special form of banded agate found in the Realms.

Description
Eye agate was similar to banded agate but with the layers within the stone arranged in concentric rings. These rings came in a variety of colors, typically gray, white, brown, grayish blue, and drab green. A typical stone had a base value of 10 gp.

Powers
Like banded agates, these ornamental stones were often ground up and used in sleeping draughts, though their effectiveness was unknown and the practice was attributed to folklore.