1964 Quarter Pattern - RB-2575, INCO

Coin Details

Description

The final entry in the RB-2xxx family of INCO experimental Washington Quarters, cataloged as RB-2575 in the Reed-Brenner classification. This test strike marks the conclusion of the second major family of alloy compositions tested by the International Nickel Company during the 1964 clad coinage development program. As the terminal composition in the RB-2xxx series, RB-2575 represents the boundary of one extensive line of metallurgical investigation. The entire RB-2xxx family — spanning thirty-one documented compositions across three sub-series (RB-22xx, RB-23xx, and RB-25xx) — constitutes a remarkably complete record of systematic alloy research applied to a specific industrial problem. From its opening at RB-2200 through this final entry, the family traced a path through copper-nickel composition space that ultimately contributed to identifying the clad formulation adopted for American coinage under the Coinage Act of 1965. With the conclusion of the RB-2xxx experiments, INCO's remaining work was documented in the RB-3xxx family, which explored yet another approach to clad composition using quarter-sized planchets dated 1964-65. Together, these three families provided the Treasury Department with the comprehensive data it needed to make one of the most consequential decisions in American monetary history.

Rarity Notes

Extremely rare. Population be 1-3 specimens. As the terminal entry in its family, RB-2575 holds particular cataloging significance.

Cross References

RB-2575 (Reed-Brenner), NGC ID: 61902