Works for me. Let's do that.
Stone Phylactery (Su): This sqecial quality of a ghost-stone replaces the standard ghost's rejuvenation special quality. Each ghost-stone is bound to a Large stone, which has hardness 8, 540 hp, and a break DC of 50, and the ghost is not capable of leaving the stone phylactery's space. If this stone phylactery is not destroyed, a ghost-stone which is reduced to 0 hp or less will rejuvenate in the stone in 1 day.
Points to consider about this:
Ghost-stone really bound to stone's space, or just within a short range?
Should hardness, hp, etc be increased if dispel evil, etc, not used first? I just took the values for 3 ft of hewn stone in the SRD.
I bumped up the rejuvenation power (no level check, faster rejuvenation) due to the phylactery.