Crystallomancy

Crystallomancy is divination by prolonged gazing at a transparent or shining surface, most often a crystal ball. The practitioner stares at the crystal until, by their own account, images, mists or scenes appear, which they then interpret. It belongs to the broad family of surface-gazing practices known as scrying, along with catoptromancy (mirror) and hydromancy (water). Psychologists see it as a way of inducing mental imagery through a fixed gaze.