PART V. Planchet Errors:

Experimental Issues:

Statehood Quarters Struck on Experimental Alloys:

Definition: In the years 1999 and 2000, some statehood Washington quarters were struck on different alloys that were deemed acceptable for use in the minting of the Sacagawea dollar coins.

The U.S. Mint conducted metallurgical tests as part of its development of an alloy for what became the Sacagawea dollar. Presumably, quarter-size planchets and dies were more convenient to use than their mini-dollar equivalents. A small number of experimental planchet state quarters are known for each of the five 1999 states: Delaware, Georgia, Pennsylvania, Connecticut and New Jersey. These dies would have been available by early 1999 for production of proof sets. Some of the experimental planchet pieces were analyzed with energy-dispersive x-ray spectroscopy to determine their composition. The predominant metal was copper, followed by zinc, with traces of manganese and nickel present.