(1964-65) Blank Pattern - RB-6000, INCO

Coin Details

Description

The opening entry of the RB-6xxx experimental blank planchet series, RB-6000 marks the beginning of a second major group of unstruck test blanks produced by the International Nickel Company. The transition from the RB-5xxx to the RB-6xxx numbering block represents a significant categorical shift within the INCO program — these blanks may differ from the RB-5xxx series in diameter (dime-sized or half-dollar-sized rather than quarter-sized), in the fundamental architecture of their clad layering, or in the family of base alloys employed. The RB-6xxx blanks collectively document a parallel line of investigation that explored compositional territory distinct from the extensive quarter-sized testing captured in the RB-5xxx series. As the foundational entry in this new series, RB-6000 establishes the baseline composition against which subsequent RB-6xxx variants would be measured. The blank preserves the alloy in its most informative state — unmodified by die striking, with the raw planchet surface, cross-sectional layer architecture, and intrinsic electromagnetic properties all available for direct examination. This piece represents the starting point of what was INCO's exploration of alloy compositions optimized for a different denomination or a fundamentally different metallurgical approach to the silver replacement problem.

Rarity Notes

R-7 to R-8. Extremely rare experimental planchet. The RB-6xxx series is among the least documented segments of the INCO program, adding to both the rarity and the research value of surviving specimens.

Cross References

RB-6000 (Robinson-Breen catalog). INCO experimental blank planchet series, RB-6xxx group, 1964-65.