RIDB-50c-1967-01 Retained Interior Die Break

Description

Preserving evidence of an unusual interior die failure, RIDB-50c-1967-01 records the first cataloged retained interior die break on the 1967 Kennedy half dollar as documented by the Cuds on Coins attribution service. The designation follows the standard naming convention: RIDB for retained interior die break, 50c for the half dollar denomination, 1967 for the date, and 01 indicating the first identified retained interior die break for this issue. Retained interior die breaks differ fundamentally from rim cuds and die cracks in their location and mechanism — while cuds form at the die rim and cracks trace linear paths across the die face, retained interior die breaks involve a fragment of die steel within the interior design field that has cracked free but remains held in place, creating a raised, slightly displaced area surrounded by design elements rather than connected to the rim. Kennedy half dollars of the 1965-1970 era were struck in 40% silver-clad composition, a transitional alloy adopted after the Coinage Act of 1965 that bonded silver-copper outer layers to a copper-silver core. The 1967 date carried no mintmark, as the Mint temporarily suspended mintmark use during the 1965-1967 period to discourage speculative hoarding during the coin shortage. Gilroy Roberts' obverse Kennedy portrait and Frank Gasparro's heraldic eagle reverse provided high-relief design elements that created stress differentials in the die steel, and when these stress concentrations exceeded the metal's fracture threshold, interior sections could separate while remaining physically retained by the surrounding die material. The retained nature of the break means the displaced fragment was not lost from the die, so the struck coin shows a raised irregular area — often with slightly different surface texture or height — within the design field rather than the smooth, featureless mass that characterizes full breaks where the fragment separates completely.

External References