Pliny the Elder, a Roman scientific writer, mentions the Druid Egg in his Historia Naturalis ("Natural History," XXIX.52). He described it as a small talisman called a "serpent's egg" that gave an unfair advantage to a Gaelic Vocontian chief who carried one during a legal battle. Pliny wrote that the Druid Egg was the size of a small apple with a pocket shell made of something like cartilage.
For our purposes, the Druid Egg is a smooth round, oval, or, yes, egg-shaped stone that can be conveniently fit in a pocket. It may be of any material including glass, and of any color. Be alert and sensitive as you look for a stone that signals to you. The Druid Egg is a tool used for developing single-mindedness. Stones are good at waiting, at not leaping into the future, therefore they can help you to stay in the present. Learn to focus your gaze and awareness on the egg until distractions die away. You will soon understand why this is known to be a tool for empowerment as it will assist you to become centered and ready to concentrate on any matter at hand.