Frame of Atiesh

The Frame of Atiesh, Greatstaff of the Guardian, is one of the three essential pieces of the staff (the others being the head and base).

Source
This item is created from 40. The Splinters are common drops from bosses in Naxxramas.

Background
When the demon lord Archimonde destroyed the city of Dalaran, where Atiesh was kept in a magical vault since the death of the Last Guardian, Medivh, the staff was believed to have been destroyed forever until the return of the lich Kel'Thuzad and his vile lieutenants. The forty Splinters of Atiesh ended up in the hands of Kel'Thuzad's henchmen, in the black citadel of Naxxramas, while Kel'Thuzad himself held the headpiece. The one piece of Atiesh that eluded him was the base, believed to have been lost in Silithus.