Gavel
A gavel is a hammer-like instrument, typically made of wood. It is used by judges and presiding officers to call for silence or to signify the finality of a ruling.
One of the more interesting events involving gavels was in 1954, when, acting as presiding officer of the United States Senate, Vice President Richard Nixon broke the Senate's gavel during a debate on nuclear energy. This gavel, made of solid ivory and held together since 1952 by silver caps, had been used by the Senate since its inception in 1789. Unable to obtain a piece of ivory large enough to replace the gavel, the Senate appealed to the Indian embassy. On November 17th, 1954 India presented the US with a solid ivory replica, which is still in use.