The surface of this weapon looks dark and pitted, and the blade, point, or head appears fragile, as if the first blow might break it.

When activated, a corrosive weapon is sheathed in acid. The acid does not harm you as long as you have the weapon in hand. The effect persists until you speak a second command word. A weapon that has this property deals an extra 1d6 points of acid damage on a successful hit.
Projectile weapons bestow this property upon their ammunition.

Prerequisites: Craft Magic Arms and Armor, acid fog, acid storm (SC 7), Melf’s acid arrow, or storm of vengeance.
Cost to Create: 1,000 gp (plus 300 gp for base item), 80 XP, 2 days.