divination of distant or future events based on visions seen in a ball of rock crystal. Divination based on an analysis of reflections in water, on polished metal, or on precious stones was practiced by early humans, who probably interpreted these phenomena as a vision of the spirit world. Scrying became widespread by the 5th century AD and was condemned by the medieval Christian church as the work of the devil.

Crystal gazing was a popular pastime in the Victorian era, together with palmistry and astrology, and it involved elaborate rituals for cleaning the crystal ball and for conducting crystal-gazing sessions, which are said to work best when the Sun is at its northernmost declination. Immediately before the appearance of a vision (which may be realistic or a mere wispy swirl), the globe is said to mist up from within.