1964 Quarter Pattern - RB-2570, INCO

Coin Details

Description

An INCO experimental Washington Quarter in the RB-2570 composition, the second-to-last entry in the entire RB-2xxx family of 1964 clad coinage test pieces. Cataloged in the Reed-Brenner system, this piece falls just one increment below the terminal RB-2575 that closes out the family. The RB-2xxx program represents one of three major families of experimental compositions that INCO produced during the 1964 testing period, alongside the RB-1xxx and RB-3xxx series. Together, these three families constitute the most systematic exploration of clad coinage metallurgy ever undertaken, testing over a hundred distinct compositions to identify the optimal formulation for mass-produced circulating coinage. The RB-2570 formulation was among the last compositions evaluated before INCO finalized its recommendations, and its proximity to the program's conclusion indicates it served a confirmatory rather than exploratory role — verifying the boundaries of the acceptable composition range rather than seeking fundamentally new alloy combinations. These terminal test pieces are of particular interest to researchers because they define the limits of the compositions that INCO considered viable, establishing the upper and lower bounds of acceptable performance for each metallurgical variable.

Rarity Notes

Extremely rare experimental issue. Population estimated at 1-3 specimens. Terminal compositions in the INCO program are exceptionally scarce.

Cross References

RB-2570 (Reed-Brenner), NGC ID: 61901