Crystal ball, for example (3)
I believe the answer is:
orb
'crystal ball for example' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for orb that I've seen before include "Ring" , "Sphere (found in regalia)" , "Spherical symbol of monarch's power" , "Ceremonial globe carried by a monarch" , "Ornamental sphere" .)