Quarter (United States coin)
A quarter dollar, commonly shortened to quarter, is a coin worth ¼ of a United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

, or 25 cents
Cent (currency)
In many national currencies, the cent is a monetary unit that equals 1⁄100 of the basic monetary unit. Etymologically, the word cent derives from the Latin word "centum" meaning hundred. Cent also refers to a coin which is worth one cent....

. The quarter has been produced since 1796. The choice of 25¢ as a denomination, as opposed to 20¢ which is more common in other parts of the world, originated with the practice of dividing Spanish Milled Dollars into eight wedge shaped segments; at one time "two bits
Two Bits
Two Bits is an American drama film. It was directed by James Foley, and stars Al Pacino, Mary Elizabeth Mastrantonio, and Jerry Barone. It was released on November 22, 1995.The title refers to the American slang term two bits for a quarter dollar....

", i.e. two pieces of eight, was a common nickname for a quarter.
For a list of Washington Quarter coins, see: Washington Quarter
Washington Quarter (U.S.)
The Washington quarter is the present quarter dollar or 25-cent piece issued by the United States Mint. The original coin began to be struck in 1932, and was designed by sculptor John Flanagan....

The current clad version is two layers of cupronickel
Cupronickel or copper-nickel or "cupernickel" is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. Cupronickel is highly resistant to corrosion in seawater, because its electrode potential is adjusted to be neutral with regard to seawater...

 (75% Copper, 25% Nickel) on a core of pure copper giving a total composition of 8.33% Ni
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...

 with the remainder Cu
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, weighs 5.670 grams (0.2000 avoirdupois oz, 0.1823 troy oz), diameter 0.955 inches (24.26 mm), width 1.75 millimeters (0.069 in) with a reeded
-Numismatics:In numismatics, reeded edges are often referred to as "ridged" or "grooved". Some coins, such as United States quarters and dimes, have reeded edges. One reason for having reeded edges was to prevent counterfeiting...