For this ability, "enemies" includes neutrals after taking the PvP setting into account.
Under the "Normal" and easier difficulty settings, the petrification lasts one round per hit die when the target is a player character. Under the harder settings, and always for non-player characters, the petrification is permanent.
A creature whose appearance is one without flesh — or is that of a basilisk, cockatrice, medusa, or gorgon — is immune to this ability. (Examples of flesh-less appearances include most golems, all elementals, shadows, and skeletons.)
This ability is similar to a monster's petrification gaze, but with a higher DC, slightly larger area of effect, and different visuals.