Sword of the Thunder God

This sword was owned by the Second Hokage. It was stolen from Konoha by Idate Morino because Aoi Rokusho told him that he could become a Chunin if he managed to get the sword. Aoi then took the sword for himself until it was destroyed by the combined efforts of Team 7.
 * Name:
 * Type:Offensive/Defensive, Weapon
 * Users: Aoi Rokusho, and Second Hokage.
 * Debut (Anime only): Naruto Episode 105

The sword glowed bright yellow and was apparently infused with pure electrical energy thus it's name. The blade was unusual in that, though it appeared to retract into or emanated from the hilt or crossguard not unlike a Lightsaber (and producing the same sound), it was apparently solid and subject to stressing and and being shattered when sufficient force was applied. The forces required were extreme however, as a weakness in the blade had to be created first with a sustained attack from Sasuke's Chidori, an extremely powerful lightning based attack itself, and then in order to actually break the sword it needed to be struck with Rasengan in the weak point that was created.

It could be speculated that this sword was extremely valuable like the First Hokage's necklace, but that was not mentioned in the episodes that it appeared. It is however extremely valuable from a combat point of view as Aoi claimed that the wielder of the blade was essentially invincible. However if one relies on the sword too much, it was proven that with skill and teamwork, a Jonin wielding the sword can still be defeated by a pair of Genin. On the other hand it is also possible that not being the proper owner of the blade and having had no formal training on its use Aoi simply did not know how to use the weapon to its full potential.