Scrying is neither a single, clearly defined, nor formal discipline and there is no uniformity in the procedures, which repeatedly and independently have been reinvented or elaborated in many ages and regions. Examples of names coined for crystal gazing include 'crystallomancy', 'spheromancy', and 'catoptromancy'. As an example of the looseness of such terms, catoptromancy should refer more specifically to scrying by use of mirrors or other reflective objects rather than by crystal gazing. There is no clear limit to the coining and application of such terms and media.

Scrying is neither a single, clearly defined, nor formal discipline and there is no uniformity in the procedures, which repeatedly and independently have been reinvented or elaborated in many ages and regions. Examples of names coined for crystal gazing include 'crystallomancy', 'spheromancy', and 'catoptromancy'. As an example of the looseness of such terms, catoptromancy should refer more specifically to scrying by use of mirrors or other reflective objects rather than by crystal gazing. There is no clear limit to the coining and application of such terms and media.