What is the name of the small hammer used in courts of law and auctions?

A gavel is a small ceremonial mallet commonly made of hardwood, typically fashioned with a handle. It is used almost exclusively in the United States in legislatures and courts of law, but is used worldwide for auctions. It can be used to call for attention or to punctuate rulings and proclamations and is a symbol of the authority and right to act officially in the capacity of a presiding officer. It is often struck against a sound block, a striking surface typically also made of hardwood, to enhance its sounding qualities.

According to tradition, Vice President John Adams used a gavel as a call to order in the first U.S. Senate in New York in the spring of 1789. Since then, it has remained customary to tap the gavel against a lectern or desk to indicate the opening and closing of proceedings, and it is also used to keep the meeting itself calm and orderly.