6/10/23 Report - Kid Finds Valuable Cent in Pocket Change. Mystery Cents. Corrosion of Sunken Modern Coins.

Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.

An eight-year-old boy found a valuable 1969-S double-die Lincoln cent in pocket change.

Here is how the article in Numismatic News begins.

A mother of a rather excited 8-year-old budding collector brought his prize cent to me recently. I anticipated it would be common. What she brought was an Extremely Fine 1969-S doubled-die Lincoln cent, which he had picked from her change. All the diagnostics were correct...

Here is the link for more about that.

Eight-Year-Old Finds Valuable Cent in Pocket Change - Numismatic News

I've looked at a lot of old cents and never found a double-die cent.  I have found a few error coins, but never a double-die error, yet they are out there.

I showed some examples in an old post, including my favorite cent with a die crack and retained cud.

Here is that link.

The Treasure Beaches Report Direct From Florida's Treasure Coast.: 12/13/19 Report - Looking More Closely At Your Coin Finds For Fun and Profit. Coin Chips and Cracks. Surf's Up.

I have some old cents, including a number of wheats that need to be inspected.  Wheat cents often show die chips on the reverse, but they are common and usually not valuable.

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Numismatic News reader Howard Sawicki has reported finding a 1983 cent that weighs 3.0 grams.

The presumption in a case like this is that it must be copper, something it shouldn’t be because all cents were supposed to have been made of copper-coated zinc in that year.

In the last few weeks I’ve shown the first known 1982-D Small Date cent struck on a Pre-82 US cent planchet that weighs the correct 3.1 grams and I’ve shown a 1983-D cent that weighs a light 3.0 grams. Both were authenticated by Numismatic Guaranty Corporation as struck on solid copper alloy planchets. However the 1983-D weighed 3.0 grams and was identified as being of a 92 percent copper alloy rather than the 95 percent copper 5 percent zinc alloy – out of specifications on both counts for a pre-1982 planchet...

Here is the link for more about that.

Search goes on for errors in copper - Numismatic News

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Yesterday I was talking about investigating the corrosion products of coins buried in different environments and how it might help if you could identify the corrosion products to get an idea of where the coins have been and therefore where they are coming from.  

I found an article that looked at the corrosion of a variety of modern coins deposited in three different aquatic environments - fresh water, brackish and salt.    Below is the abstract and conclusion of the study.

Two types of pennies (new and old), dimes, and nickels were placed in three different aquatic environments, allowed to corrode, and periodically analyzed. Methods for analysis included scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and powder X-ray diffractometry (XRD). Coins exposed to salt water, at Emerald Isle Marsh and Anderson Dock, had more severe corrosion than coins in freshwater, at Bent Creek. A total of eight minerals were identified as copper corrosion products. No nickel corrosion minerals developed on any of the samples...

Conclusion

A total of eight minerals were identified to form as corrosion products (Table 1). Coins exposed to salt water at Emerald Isle Marsh and Anderson Dock had more severe corrosion than coins in freshwater at Bent Creek. The conductive nature of salt water due to electrolysis increases the rate of corrosion in saline environments. Emerald Isle had the most corrosion minerals, including copper minerals atacamite, bornite, chalcocite, connellite, and cuprite; and zinc minerals simonkolleite and smithsonite. Anderson Dock contained the same minerals, excluding bornite, connellite, and smithsonite. Conversely, malachite was the only corrosion mineral identified on Bent Creek samples, but no zinc minerals. No nickel corrosion minerals were identified on any coins in any environment. Further research regarding the release of nickel from metal alloys, influential factors promoting the release of nickel, and mobility of nickel within the environment, may help explain why no nickel corrosion mineral formed. The results of this study will benefit forensic science by illustrating how coins weather with time under certain aqueous conditions. Furthermore, the United States Treasury and other metal users could use the findings of this study for developing improved protection against the corrosion of coin currency and metals it contains. 

Here is the link for more about that.

A_Griesmyer_Corrosion_JrnlUngRes_2013.pdf (uncg.edu)

I'm not surprised by the finding that salt water was more corrosive.  I think most of us knew, or at least, suspected, that.  In fact, I've written about the nice blue patina found on coins detected in fresh water northern lakes, as opposed to those found in salt water.  I commented on a nice silver fresh water coin found in a Minnesota Lake in a 2015 post, as well as other posts.

The Treasure Beaches Report Direct From Florida's Treasure Coast.: 4/7/15 Report - Patination and Toning Of Coins.

I was surprised to find an actual study on corrosion of modern coins.  Now I need to learn to recongize the various corrosion products.

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Nothing new on the National Hurricane Center map of the Atlantic.

The Treasure Coast surf is running about one foot.  That will be the case for about a week.

We have a west wind this morning.

Good hunting,

Treasureguide@comcast.net