1964 Quarter Pattern - RB-2500, INCO

Coin Details

Description

Opening the third and final sub-series within the RB-2xxx family, this experimental Washington Quarter is cataloged as RB-2500 and represents a new phase of INCO's 1964 clad coinage research. The jump from RB-2375 to RB-2500 in the Reed-Brenner catalog indicates a major shift in the experimental approach — the RB-25xx compositions explored a fundamentally different alloy system or bonding methodology than the earlier RB-22xx and RB-23xx groups. By mid-1964, INCO's research team had accumulated extensive data from hundreds of test compositions and was converging on the formulations that would ultimately be recommended to Congress. The RB-25xx sub-series may represent the final phase of optimization, testing compositions in the immediate neighborhood of the most promising candidates identified through earlier work. Alternatively, this sub-series explored backup compositions designed to serve as fallback options if the primary candidate proved problematic during scale-up to full production. In either case, RB-2500 marks a significant milestone in the experimental program, representing the beginning of a new and distinct family of alloy experiments that would produce another sixteen documented composition variants before the series concluded at RB-2575.

Rarity Notes

Extremely rare. Population estimated at 1-5 specimens. As the first entry in a new sub-series, RB-2500 was produced in slightly larger quantities for baseline testing.

Cross References

RB-2500 (Reed-Brenner), NGC ID: 61889