1937 Washington Quarter. Proof-67+ (PCGS). CAC. Virtually pristine, universally reflective surfaces are dusted with pale silver and gold iridescence. The second rarest issue in the Proof Washington quarter series after the first year 1936, the 1937 boasts a relatively limited mintage of 5,542 coins. Far finer than most, the premium Superb Gem offered here would do justice to the finest collection.