Any gemstone (or the toadstone) that was formerly regarded as having protective or curative powers, either medically or psychologically, by reason of itsalleged magical powers as a stone, without regard to the stone being a precious stone or even a rare-stone, or to the setting (some inferior stones of this kind were set in superior-quality fingerrings).Various stones were considered to be efficacious against certain specific aliments or types of accident. Such beliefs were especially prevalent during the Middle Ages.