The term refers to a United States one-cent coin mistakenly struck in silver-colored planchets instead of the standard copper-based alloy during the year 1943 at the San Francisco Mint. These anomalies are highly sought after by collectors due to their rarity, stemming from an error in the minting process during wartime metal conservation efforts.
The significance of these pieces lies in their deviation from the norm and the historical context surrounding their creation. In 1943, the United States Mint switched to using zinc-coated steel for cent production to conserve copper for the war effort. The presence of silver-colored examples struck with a “S” mint mark indicates a production error of significant value, both monetarily and historically, providing insight into minting procedures and material handling during a crucial period.