Crystal gazing may be used by practitioners—sometimes called "readers" or "seers"—for a variety of purposes, including to predict distant or future events, to give character analyses, to tell fortunes, or to help a client make choices about current situations and problems.
The stereotypical image of a Romani woman wearing a headscarf and telling fortunes for her clients by means of a very large crystal ball is widely depicted in the media and can be found in hundreds of popular books, advertising pages, and films of the 19th, 20th and 21st centuries.
Books of instruction in the art of crystal gazing often suggest that the ball used should be perfectly spherical (that is, without a flat bottom) and should be supported in a wooden or metal stand.
Most authors suggest that the work of crystal gazing should be undertaken in a dimly-lit and quiet room, so as to foster visions and more easily allow the onset of a trance state.
[3][4] The psychologists Leonard Zusne, Warren H. Jones in their book Anomalistic Psychology: A Study of Magical Thinking (1989) have written: Morton Prince (1898, 1922) was an early investigator of crystal gazing and one of the few to ever subject it to scientific scrutiny.
The subject had previously experienced hallucinations when looking at reflective surfaces, something which tends to be true of most people who experience visions when gazing at crystals.