Undeath to death

Undeath to death was a necromancy spell that destroyed undead.

Effects
The spell extinguished the "life forces" of undead beings within a 50-foot-wide (15 meters), which immediately slew them if they could not resist in some fashion. Only a limited number and power of undead creatures could be slain, beginning with the weakest and those closest to the center of the burst.

Components
As well verbal and somatic components, the spell required a material component in the form of crushed diamond powder valued at 500 gp, while priests also needed a divine focus.