Elfstones are magical gems that channel the Will of the user and are capable of great miraculous but also destructive powers. It takes a great amount of physical stamina away from the uer and thus are utilized seldom. If the bearer dies while using them, they are destroyed. Very few Elves ever had the Will to use them, with the exception of the Shannara family that had a strong affinity for magic.
There are several kinds. The blue stones are Seeking Stones while the green are Stones of Protection. There also purported to be a black Elfstone of unknown abilities.
Over the centuries most had been destroyed or lost to the Elves's knowledge and considered extremely rare or even a myth, while most Elves did not know they ever existed.
Shea Ohmsford was the last known person to use Elfstones.