|Editing:||Please feel free to edit constructively!|
A weapon with this crystal attached does an extra 1d6 points of damage to anything with an immunity or partial immunity to critical hits or precision damage that was not granted by a type, subtype, or racial ability, such as the effects of Fortification.
As the least crystal and the weapon reduces the amount of immunity they have by half for 1 round. If they had full immunity they now only have a 50% chance to negate such things, etc.
As the lesser crystal and on a successful critical, the immunities are completely negated for 1d4+3 rounds.