Coin Monday: A dime worthy of Dali

June 1, 2009
Posted by John Dale

In past Coin Monday posts, I’ve made clear my love for error coins. They fascinate me, both for what they can teach about the minting process and for the mildly transgressive charm of their blatant imperfections (A coin-as-humorous-gift that I’ve been waiting to spring on someone is an inexpensive error coin, paired with a handwritten note that reads “Nobody’s perfect.”). I was cataloging recently for Heritage’s July Summer FUN auction when I came across a small batch of error coins. One in particular stood out: a 1918-dated dime brockage.

As dramatic as other errors might be, few are as surreal as the brockage; one side is perfectly normal, but the other side is a mirror image of the first, with the features sunk into the coin instead of raised and the lettering reversed. A brockage results from a glitch in striking. In the modern minting process, a blank planchet is fed between two dies, one lower die or anvil die that does not move, and one upper die or hammer die that is raised and lowered. (The terms anvil and hammer are holdovers from the time when coins were made by hand. A heated planchet was placed on the lower die, the upper die went on top of the planchet, and the broad top surface of the upper die was struck with a mallet or hammer.)

Normally, a planchet goes between the two dies, receives an impression, and then the newly minted coin is ejected to make room for the next planchet. Rarely, though, a newly minted coin sticks to one of the dies. When the next planchet comes in, instead of being struck by two dies, it gets its design from one die and one coin. The coin-as-die is in positive relief, so it gives the planchet a negative impression, and since the coin-as-die shows the side opposite that of the die to which it is stuck, the brockage side of the error mirrors the normal image.

In the case of this 1918 brockage dime, a coin stuck to the reverse die, and this piece was then struck with the obverse die, which created the normal impression, and the obverse of the coin-as-die, which is responsible for the mirror image. Both sides are well-centered and show sharp impressions of Miss Liberty but relatively weak letters and numbers; interestingly enough, the word LIBERTY and the date are more clearly defined on the brockage side. Though this dime is dated (twice!), the mintmark is missing, and where this error was made remains a mystery. Its absence, however, will hardly dampen error collectors’ enthusiasm for this double-headed treat. It’s just the beginning of what promises to be a great Summer FUN auction.

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-John Dale Beety