crystal ball

"The Crystal Ball" by John William Waterhouse: scrying in crystal

crystal ball (plural crystal balls)

1. A globe of glass or crystal used to foretell the future.

   The psychic looked into the crystal ball and saw into the future.

2. (by extension, used mostly in the negative form) A way of seeing into the future.

   If her past is a crystal ball to her future, she will perhaps never be rich, even though she is a good, kind, educated, hard-working person.

• orbuculum
• showstone, shew stone

• scry