1964 Quarter Pattern - RB-2210, INCO

Coin Details

Description

A Washington Quarter-format test strike from the International Nickel Company's 1964 experimental program, cataloged as RB-2210 in the Reed-Brenner classification. This piece continues the systematic exploration of copper-nickel clad compositions within the RB-22xx sub-series. Each specimen produced by INCO carried precise metallurgical documentation identifying its exact composition, though much of this documentation has been lost over the decades. What survives is the RB numbering system, which Kevin Flynn developed by correlating surviving INCO records, physical analysis of known specimens, and archival Treasury Department correspondence. The RB-2210 composition would have been evaluated against multiple criteria established by the Treasury Department and the Mint Bureau: the alloy needed to approximate the electromagnetic signature of silver coins so that existing vending machines would accept them, it needed to resist tarnishing and wear at least as well as silver, it needed to be economically viable for mass production, and it needed to be sufficiently difficult to counterfeit. INCO's testing program ultimately demonstrated that a pure copper core bonded with 75% copper / 25% nickel cladding layers met all these requirements — the composition that was adopted for dimes and quarters under the Coinage Act of 1965 and remains in use today.

Rarity Notes

Extremely rare. Population estimated at fewer than 5 specimens. INCO experimental quarters are among the rarest 20th-century American numismatic items.

Cross References

RB-2210 (Reed-Brenner), NGC ID: 51737