Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.
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Coin No. 4 After Two Days of Vinegar
Now Showing "LIBERTY" |
Today I'm continuing with the coin cleaning illustration that I started yesterday. I soaked the three coins that remained unidentified another day to see how that would work.
I'll start with the coin that looked like it might be clad (shown above). More material was removed by the additional day of soaking, but few additional details emerged. What was revealed is the word "LIBERTY." That is about all that I could see after two days of vinegar. Not only has most of the corrosion been removed but perhaps also some of the outer surface that covered the copper core of the coin. I don't think additional cleaning will help. The surface detail does not seem to exist anymore. And it is only a clad coin anyhow.
Now let's look what the additional cleaning did for coin number 1. All I could see on that one after twelve hours of soaking was "TED," which was undoubtedly part of "UNITED STATES of AMERICA." This one, unlike coin no. 2, had a good rim remaining.
Here it is what it looked like after another day of soaking in vinegar.
It isn't easy to see it in this photo, so I'll zoom in on the letters (below).
So the additional day of soaking helped some, but not a huge amount. The most of this coin's surface still shows hardly any details, but one other clue did become evident. You can see that small but important detail in the picture below.
Look near the rim at the six o'clock position. There is a curved line that goes to the right and up. Do you know what that is?
Look at the Mercury dime below and see if you can see a similar line.
Look at the lower boundary of Mercury's neck. That is the line you see on the no. 1 coin shown above. From this small detail it looks like the no. 1 coin is a mercury dime. The neckline on Roosevelt is different.
So, I think no. 1 is a mercury dime, but I don't know the date or much of anything else about it, and I doubt that additional soaking in vinegar will do much more.
I'm considering following up with either electrolysis or tumbling just to see how it would work. I don't think either would do much good at this point, but it might be a learning experience.
Now moving on to no. 2. After the additional day of cleaning, no. 2 still shows almost nothing, and I can't tell anymore about it even after two days of vinegar. It does appear to be silver. Maybe I'll test one more cleaning method on it.
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| Coin No. 2 After Two Days of Cleaning. |
My best guess on this one is that it is another mercury dime but I have very little to go on. Again, it might be interesting to try another method of cleaning. I don't know if any details or clues might be teased out.
To sum it up, vinegar did a fairly good job of removing surface corrosion. On some cases, one day was about enough, but a second day of soaking helped a little.
On badly corroded coins, the vinegar treatment helped a little, but there was only so much you could expect. Harder cases may require other methods, but vinegar is a fairly good method to begin with. In the future I might see how other methods work on the more difficult of these coins.
If you are using the vinegar method with multiple coins, I'd recommend putting coins made of different metals in different containers. For example, I put those appearing to be silver in one container and the clad coin, which much more copper, in another container.
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I find the problem-solving process interesting. In this case the problem is object identification, which shares a lot in common with many other kinds of problems, such as recognizing coin distribution patterns on a beach, identifying beach conditions or even identifying metal detector targets. It has a lot to do with matching patterns.
Here are some of the basic principles.
The Classical Grouping Principles
Wertheimer (1923) identified several laws of perceptual grouping that describe how elements are organized into unified percepts.
Proximity. Elements close together tend to be grouped together.
Similarity. Elements that share features (color, size, shape, orientation) tend to be grouped.
Good Continuation. Elements arranged along a smooth contour tend to be grouped.
Closure. The visual system tends to complete incomplete figures, filling in gaps to perceive closed forms.
Common Fate. Elements that move together tend to be grouped together.
Later additions to the classical set include three further principles.
Common Region. Elements within the same bounded area are grouped.
Element Connectedness. Elements that are physically connected are grouped.
Synchrony. Elements that change simultaneously are grouped.
The overarching Gestalt principle is Prägnanz (sometimes translated as "good form" or the minimum principle): perceptual organization tends toward the simplest, most regular, most symmetric interpretation consistent with the sensory input. A complex figure will be perceived as composed of simpler sub-figures; an irregular shape will be seen as a distorted version of a regular one. This principle has been formalized in information-theoretic terms as a preference for the interpretation with the shortest description length.
Maybe you realized you were using some of these as you tried to identify the coins.
Self-awareness can be fun and helpful.
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The surf is very flat this week. Salvage season should be well underway.
There was some tropical development down by the Yucatan which is not threat to the United States.
Good hunting,
Treasureguide@comcast.net
