1970-S Kennedy Half Dollar
Struck on 1.4g Aluminum Planchet
PCGS PR 64
SOLD

This is an amazing and spectacular proof major mint error. It is a 1970 Kennedy Half Dollar from the San Francisco Mint that was struck on an aluminum Shell Gas token. Even though the PCGS describes this as struck on an aluminum planchet, it has been determined to be on an aluminum Shell Gas token.

In 1969 and 1970, the Shell Oil Company issued a State of the Union coin game booklet as part of a promotion for their gas stations. People collected these aluminum tokens of each of the 50 states and got prizes.

The United States Mint did not strike aluminum coins for circulation. Somehow, three of these aluminum Shell tokens were accidentally mixed in a bin of blank planchets or deliberately taken in. It is also unclear whether these were intentionally made or struck during the normal minting process. Furthermore, they were either taken out of the Mint or surfaced in sealed proof sets where a lucky collector discovered them.

Proof coins are struck by technicians who hand feed the blanks into special presses. They are produced, examined and packaged using extreme quality control. It is very unusual to find major proof errors. A few broadstrikes, off-centers, double strikes (in collar) and off-metals have been known to be found in sealed proof sets. Proof errors are aggressively sought after by many error collectors.

Off-Metal Errors are featured in my
NLG Award winning book,
World's Greatest Mint Errors.