c.1964 Quarter Pattern - P-5391, DuPont

Coin Details

Description

A second experimental quarter composition from DuPont's clad coinage proposal, struck on a Washington quarter-format planchet in a different alloy formulation from P-5389. DuPont submitted multiple compositions for evaluation, each representing a distinct metallurgical approach to the challenge of creating a coin that would be durable, aesthetically pleasing, resistant to counterfeiting, and compatible with the vast installed base of coin-operated machines across the country. Vending machine compatibility was a particularly demanding requirement — the new coins needed to match silver's electromagnetic properties closely enough that existing coin mechanisms could accept them without costly modifications to millions of machines nationwide. P-5391 tested a different balance of metals from its siblings in the DuPont series, exploring the range of possible formulations that might satisfy these competing technical requirements. The failure of DuPont's bid did not represent any deficiency in the company's materials science capabilities, but rather reflected INCO's advantage in having developed a composition that more closely replicated the electrical conductivity profile of the existing silver coinage.

Rarity Notes

R-8+ (Extremely Rare to Unique). DuPont experimental patterns survive in minimal numbers, as most were returned to the Mint or DuPont after testing.

Cross References

Pollock P-5391. Part of the DuPont experimental clad coinage series (P-5389, P-5391, P-5393).