The Silver Half Dollar's Blog

27 Mar 2021

The Glass Cent

Young Numismatists Exchange | The Silver Half Dollar

In the middle of World War II, the United States government desperately needed copper for ammunition and other military equipment. The War Production Board was refusing to allocate enough copper to the United States Mint to produce enough cents for the year. The Mint began its own experiments on alternative materials such as steel. At the same time, the Mint invited private companies to test out various types of plastics in case all metals were unavailable due to the war.

John Sinnock, a Mint engraver, produced a pair of cent-sized metal dies to loan to the companies that attempted to produce a prototype. The obverse featured a portrait of Liberty that had been copied from the Columbian 2 centavo coin. The reverse featured a simple wreath design with the words “United States Mint” in the center of the wreath.

One of the alternative materials that had prototypes of a cent made was glass. In 1942, the Blue Ridge Glass Company of Kingsport, Tennessee produced at least 2 prototype cents. The United States Mint provided them with a pair of the aforementioned dies.

But how were these glass cents even made though? Wouldn’t they simply shatter under the pressure necessary to strike a coin? Corning Glass Company provided Blue Ridge Glass with tempered glass “blanks”. The glass “blanks” had to be heated up to just below the melting temperature of glass, which is roughly 2600 °F. The dies also would need to be extremely hot. The glass then had to quickly cool to ensure that the design would be preserved. Unfortunately, Blue Ridge Glass was unable to heat the die, resulting in softly detailed experimental cents. Weakness of the strike was especially apparent on the E within Liberty and the J in Justice. The edges of the coins were then manually smoothed out, which would cause varying weights of the coins should many be produced.

These coins would never have lasted should they have ended up becoming the next cent composition. Blue Ridge Glass had some of their employees carry some of the “blanks” in their pockets for a few days to test their durability, but they chipped and created extremely sharp edges quickly. In addition, of the two coins that have been known to be struck, only one of them is even intact. The other one is broken in half, making the other example a unique piece.

Weighing roughly 1.52 grams with a diameter of 19.85mm and a thickness of 2.36mm, the only fully intact piece is graded PR64 Red Brown by PCGS.

In the end though, the steel cent won out above the glass cent and the numerous other prototypes submitted to the mint.




Level 4

very intersting. I had never even heard of these glass cents.

Never knew about the glass prototype. When I read about the glass, I knew it wasn't gonna work.


Level 4

Never knew this was tried.


Level 5

Never heard of this peice.... thanks!


Level 6

Well done blog! Really interesting subject! Thanks for your research. ; )

Long Beard

Level 5

Some of these proto-types show up at auction from time to time. I saw a bakelite centl not long ago, my memory can't recall which auction house at the moment. Kagin's I'm thinking for some reason. Nice topic though!


Level 6

Most people don't realized that glass is a VERY tough material if made to be that way. I see a problem with the struck coins being cooled and tempered correctly. That is what likely led to chipping. All glass isn't plate window glass. Interesting read. Thanks.


Level 5

Very interesting history lesson. Thanks

The MoKe

Level 6

Roger Burdette wrote an excellent book on this subject. "United States Pattern & Experimental Pieces of WW II". Well worth a read if the subject interests you.


Level 7

They were a bad idea from the start. But when your in a war and people are dying you try anything. That's what they did. Thanks for the blog and it's history.

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