Moss agate

Moss agate was one of many forms of quartz agate found in the Realms.

Description
Impurities of manganese formed grayish green fern-like patterns that resembled moss embedded in these pink to yellow-white semi-transparent or translucent ornamental stones. Moss agate took a bright polish and was occasionally used for inlay work on coffers and other fine furniture. If the moss pattern formed a significant design, like an eye or a circle, this stone might be used in a ring or pendant in a polished cabochon. A typical stone had a base value of 10 gp.

Powers
Moss agate enhanced serenity and increased stability so it was used in powdered form in sleeping draughts and in all manner of potions to assist the mixing of components that might otherwise clash. Its powers were such that it could be safely added to any potion and even failed attempts did not explode or turn poisonous.