This is a small adamantite loop and handle which will be useless in any but a magic-user's possession, and any other class touching a talisman of this sort will take 5-30 hit points of damage. 

When held by a magic-user concentrating on control of a sphere of annihilation, a talisman of the sphere doubles the Intelligence bonus percentage for control, i.e. 2% per point of Intelligence from 13-15, 6% per point of Intelligence from 16-18. If control is established by the wielder of a talisman, he or she need check for continual control only every other round thereafter.

If control is not established, the sphere will move towards the magic-user at maximum speed (16-ft/round). 

Note that a wand of negation will have no effect upon a sphere of annihilation, but if the wand is directed at the talisman it will negate its power of control so long as the wand is so directed.