Great Sunder( Psionics Handbook 3.0, p. 0)
You can sense the stress points on others' weapons.
When you strike at an opponent's weapon, you ignore half of the weapon's total hardness (round down). 'Total hardness' includes any magical or psionic enhancements possessed by the weapon that normally add to its hardness. However, to strike and do any damage 10 a magically or psionically enhanced weapon, you still need a weapon of equal or better enhancement.
You can also sense the stress points in any hard construction, such as wooden doors or stone walls, and can ignore half of the object's total hardness (round down) when attacking that object.