2017-03-22 Wed

A pair of Proof 1964 Jefferson 5-cent coins, stuck together is offered from 26th April to 2nd May by Heritage’s auction. This mated pair error remained together after they were removed from the coining press. Being a proof coin, they should have been detected and rejected. Mated pairs of circulation coins are very rare.

A coin was stuck on the obverse die and the coin’s reverse became a surrogate die to strike the next planchets. The obverse rose higher and wrapped around the top of the obverse die due to the powerful strikes and the presence of two coins in the die chamber. The reverse stuck on one or more planchets, distorting the Monticello design. Another coin was fed in which struck between the reverse die, and the reverse of the earlier coin.

The obverse of the second coin features a faint Jefferson’s portrait created by the obverse die through the die cap. The obverse of the second coin has a distorted brockage image formed by the fading image on the reverse of the first coin. The reverse design started distorting due to the pressure of the strikes.