Undeath to Death

(Player's Handbook v.3.5, page 297, DnD 3.5)

Necromancy

Level: ; Cleric 6; Sorcerer/Wizard 6; Sha'ir 6; Death Master 6; Urban Druid 6; Dread Necromancer 5
Components: V, S, DF
Area: Several undead creatures within a 40-ft.-radius burst
Saving Throw: Will negates

This spell functions like circle of death, except that it destroys undead creatures as noted above.
Material Component: The powder of a crushed diamond worth at least 500 gp.