What if it's part of a sunder attempt?
Crystalbrittle (Sp): X/day, a ch’i-lin may reduce the hardness of a weapon it strikes as part of a successful sunder attack by 5. This reduction in hardness applies to the initial sunder attempt and lasts for 10 rounds. In addition, rolling a 1 on an attack with the targeted weapon causes it to take damage equivalent to the amount it would have dealt on a successful hit. This is the equivalent of an Xth-level spell.
If it's a touch attack, you mean a touch against the creature holding the weapon?