I guess I'll try my hand at this.
The Sword of Stone
Legends spoke of an immense golem, said to have been carved from a mountainside. No one knows who created it, but it ravaged the lands with a force comparable to a raging dragon. It crushed armies, destroyed cities, and slaughtered foolhardy adventurers brave enough to face it. It could not be stopped...

The golem continued it's path of destruction, heading towards the capital city. All that remained to defend the city was an unknown order of Paladins. The battle was epic; All the Paladins were killed except one: Byrna Warpcross. With his final blow, he drove his sword into it's head. Once the sword was fully embedded in the golem, it sank into the earth, submerging all but it's massive head; The sword still entombed within it's stone skull. The sword remained in the golem for thousands of years, absorbing the power of the golem.

The Sword of Stone appears to be made of stone but is much lighter than it seems. The sword functions as a +5 vicious longsword. It grants it's wielder DR 10/Adamantine. It also allows the wielder use a slow effect (DC 30 Will save) 5 times/day on a successful hit. On a critical hit, the target creature is immediately petrified (DC 35 Fort save). This sword also has a curious effect on constructs. On the equivalent of a critical hit, the construct completely stops functioning as if petrified (no save). This effect includes living constructs such as warforged.