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Monday, January 9, 2023

1/9/23 Report - Surface Characteristics of Fake Coins. Using Fluorescent Light On Coins. Wreck of the HMS Erebus.


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


Normal 2022 P Quarter Viewed Under Black Light.

I recently mentioned an article from Numismatic News telling how coin experts and authenticators use fluorescent light to view coins. ( See Fluorescent Light Coin Examinations - Numismatic News)

The author said, Now, you’ll get no argument from me that bagmarks, scratches and hairlines are the easiest to see when you tip and rotate a coin in a dark room using incandescent light as is done in every professional grading room, but the glare from that light can hide friction on the high parts of the coin’s design. A stereomicroscope is the “equalizer.” Anything that can be seen using incandescent light can also be seen (plus more) by using fluorescent light, both eyes and the microscope. That’s why I examine just about every coin I grade with both a 7X hand lens under a 100 watt incandescent light and a 7X scope illuminated with fluorescent light. I like to see all the coin’s attributes. The only advantage of fluorescent light used with a hand lens is the ability to see rub (loss of luster) on a coin’s high points that is hidden by the glare from a light bulb! Give it a try.

Ok, so of course I'll give it a try, but I don't have the specific equipment recommended.  The magnification of my microscope is sufficient, for sure, but it not stereoscopic.  And I have an old block light that I've used with great satisfaction for viewing other types of finds.  I don't know the specs for it though.  Never mind.  I'll forge ahead with what I ahve and see what I can learn.

Above you see a plain 2022 quarter photographed using my substandard equipment.   Below is a photo of the same quarter using the same equipment, but with incandescent rather than fluorescent light.


Same 2022 P Quarter Photographed Using Incandescent Light Coming From An Angle.


So far I don't see anything that jumps out when I use fluorescent light on the quarter.  It might be missing something that an expert eye would see.  But my experiment has just begun.

I'll have to go back and do that for comparison some other time.  If I moved the quarter to the left, I wouldn't have the shadow on the front of the face.

I took a lot more photos using both incandescent and fluorescent light but can't find them on my thumb drive right now, so I'll have to go back and take more photos.  

In addition to the quarter, I was going to use a 16th century Charles and Joanna two-reale.  I'll complete that experiment some other time and post it when I get it done.

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I found a good article on detecting fake coins.  Here are a couple paragraphs.

When two dealers get together to discuss a suspect coin you’ll often hear them mention a rough, granular surface or pimples. These characteristics are commonly found on fakes made by casting.
More recently, they are seen on fakes struck using dies made by a spark erosion process. Many of the new Chinese counterfeit coins have these defects and they cannot be polished off without affecting the coin’s design. Do you see the tiny pimples in each of the micrographs?

One note of caution is in order. I have found that sooner or later, every defect seen on a counterfeit will turn up on a genuine coin and the reverse is also true. For instance, environmental damage can give a genuine coin a rough granular appearance and a few stray pimples on a coin does not prove it’s a counterfeit. In fact, one variety of 1883-CC Morgan dollar is covered with little pimples on its reverse.

And here is a link to read more.



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A team of Canadian archaeologists recovered 275 artifacts from the wreckage of the HMS Erebus in September. 

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