7/6/15 Report - Corroded Silver Coins. Corrosion As A Clue. Coins and Layers of Sand.

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

 As you know finds come in a variety of conditions.  Some come up looking like they were lost yesterday and some barely survive.

Of course some were lost just yesterday, but some that were lost long ago, still look very good, while others that aren't as old have deteriorated to near nothing.

Silver shipwreck cobs are the same way.  Some show great full detail, while others are worn away to just a fraction of what they once were. The two sides of the same coin can be very different too.

It is very common for cobs that are found on an ocean beach to have lost as much as one third of there original weight.

As I said yesterday, I've been looking at some old finds that I never really looked at very well.  In that group were a good number of Rosies and Mercs in various conditions.

Here are two of the Mercury dimes in not terrible condition.

As you probably know, silver tends to turn black, especially when it has been in sea water.

On the other hand, silver dimes that I've found in cold fresh water lakes up North, have a more gun metal blue patina and very little erosion.

The two mercury dimes above were found on Florida ocean beaches.  I don't recall exactly where.

The second one (1934) is more corroded than the top one (1941) and shows sand still adhering to the surface.

The third is also a silver dime.  This one is much more corroded.   You can't tell if it is a Rosie or Merc or what.  It does appear to be a dime though.

Notice that it also has sand still adhering firmly to the surface.  That tends to cause a mottled rough surface that is very commonly seen on more corroded silver dimes that come from an ocean beach.

I went through several that looked like this yesterday, as well as some that were worn paper thin and some that were worn completely through in some places.

Those that were paper thin were either still round though.

Some reales show the same type of corrosion.  This half reale was found at Jupiter and has one very crisp side.  The side shown in the photo was completely covered with a thick shell crust when it was found.  The other side had no sand sticking to it and that side was completely visible when dug, but the details aren't as crisp.  It seems the sand shell on the one side protected and maintained the surface of the reale.  After the sand shell was cleaned off using Muriatic acid, I saw what you see here.

Exactly how one side was so heavily encrusted and the other side not at all, I don't know.  My theory is that it rested in the sand dunes for hundreds of years unmoved.  It is hard to explain how one side attracted sand and the other side not at all.  Other cobs have been found paper thin, but still showing good detail.

Here is an uncleaned dime, which seems to have lost silver in a way that is relatively unusual for a silver dime.  They often maintain the round shape even when severely corroded.  I've seen very few silver dimes that have lost the round shape like this one.

On this one you can still make out some of the detail on the side shown in the photo.  There is no detail that can be seen on the other side.

If you look at the amount of wear, or lack of wear on a piece of silver, you might get some clue about where it has been.  If you can figure out where they have been, then you will better know where to look to find more.

Unfortunately I don't know now where these dimes came from.

I do know exactly where the half reale came from, and I am pretty sure that it just washed out of a sand dune before it was dug up.  I suspect that it was in the dune undisturbed for hundreds of years.  Undoubtedly in that time it was washed over by sea water at least a few times.  Perhaps that accounts for how one side got encrusted but not the other.

My main point today is that if you pay attention to your finds, you might get some clue to the source and therefore know where to look for more.

I suspect that coins that lose a lot of material, like the irregular shaped dime shown above, at some point was in the churning sand in the shallow water.  In contrast, I am pretty sure that was not the case for the half reale.

As a side note, I've coins found in acidic black soil around mangrove trees really corrode and dissolve.

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A few days ago you saw in this blog how old shipwreck coins and items were found using blowers near shore.  A good bit of sand had to be moved to expose those items.  There are two ways that such items would have ended up under feet of sand.

Items that were lost during a hurricane might have been lost when tons of sand had just been removed and found their way down to near bedrock right away.

The other way is that items could be lost on top of layers of sand, either in the water or on the beach or on the dunes, and then gradually found their way to lower levels over the years and centuries.

Each time a layer is removed, the objects go deeper.  Sometimes they are covered again by new layers and remain there under the new layers until new erosion removes sand to deeper depths.

And of course there are times when coins and things are washed up with the new sand.  The coins that most recently washed up will then be in layers of sand above those that were in layers that previously eroded.

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It looks like the surf on the Treasure Coast will be just a touch bigger this week, but not very much at all - it is still a smooth surf.

Happy hunting,
Treasureguide@comcast.net

4/15/15 Report - Different Detectors For Different Beach Hunting Jobs. Rosie and Merc.

Written by the TreasureGuide for the exclusive use of treasurebeachesreport.BlogSpot.com.

Two Silver Dimes With Different Patinas.

Before I start my main topic for today, here are two dimes with different patinas.  The Rosie is a 1963 that was graded by a coin dealer as proof.  The Merc is a 1944 and was graded AU.

The Rosie has a lot of lustre.  The Merc is more the color that you might expect, but the surface is duller.

Under magnification you can see that the bluish color on the Rosie is a very thin coating that has not affected the sharpness of the coin's details.   Both have been stored in a plastic coin holder for a good twenty plus years.

Just an example.  Now on with my main topic for today.

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Yesterday I began a comparison of three different types of metal detectors that could be used for beach hunting, but I only got the first done.  Today I'll get to the other two.

The purpose of talking about these three detectors isn't so much about the three specific detectors, it is more about how different types of detectors have different strengths and weaknesses and about how strategic decisions of detector selection should be made.  This discussion is therefore not a detailed analysis of each of the detectors or a analysis of depth or performance, but rather more of a discussion of features and how those features help determine how different types of detectors might be used strategically.

I started with the Ace 250 yesterday, which is a detector that would be a decent choice if and when the strategy is to quickly sift through dry sand for modern coins and jewelry, especially when there is some junk.  The disadvantage of the small stock coil on the Ace is compensated by the ability to quickly pinpoint and identify targets and the ability to hunt close to metal obstacles such as beach chairs.

The Excalibur is used by many Treasure Coast beach hunters who tend to be more oriented to old shipwreck items.  Treasure Coast beach hunters, as contrasted with South Florida beach hunters, tend to focus more on targeting old shipwreck items and generally hunt less crowded beaches that are visited by more conservative beach-goers.

The Excalibur, of course, costs about four or five times what the Ace costs.  The Excalibur is water proof and can be submerged for water hunting.   That makes it more versatile.  If you want similar performance at half the price and don't need a waterproof detector, the Minelab Sovereign would do about the same job while costing less.

Unlike the Ace, the Excalibur has simple linear discrimination.  One discrimination knob is used for discrimination and another for sensitivity.

The Excalibur is simple to operate.  There is no ground balancing.  It performs about equally well in dry sand, wet sand and under water.  It will do a good job almost anywhere on a Florida beach.  You can start in wet sand and decide to scan a little dry sand or go into the water and dive with it. That is all good and easy.  You can discriminate but even with no discrimination, the Excalibur is not as hot for iron as some detectors.

The biggest difficulty that I see with the Excalibur is with the casual detectorist who tries to use the Excalibur in the wet sand in motion mode.  The less experienced detectorists can find detecting difficult where the water is coming and going.

I once had a guy come up to me and ask me what settings I was using because he saw me working the wet sand where the water was moving in and out and he was trying to do the same and was having trouble.   The main difference was that he was working in the motion mode and hadn't made any other adjustments, while I was using the pinpoint mode, as I almost always do with the Excalibur.

Anyhow, the Excalibur is a good sturdy general-purpose detector with some discrimination that has a good response to gold and small targets such as small cobs or small gold rings.  If you are hunting shipwreck items in wet sand, it is an easy choice over the Ace, whereas if you are hunting the dry sand, the Ace might be the best choice in some situations.  The Ace is also much lighter to swing on dry land.

While the Excalibur is used by many on the Treasure Coast, the Minelab CTX 3030 is very prominent on South Florida beaches.  The CTX costs about twice as much as an Excalibur.

The CTX has a lot more features and settings than the Excalibur, including a screen for target ID, various program selection, GPS, etc.  Instead of a few knobs, the CTX provides a lot of flexibility and options.

South Florida beaches have a lot more valuable modern jewelry and that is what the hard-core guys down there focus on most of the time.   It is also easier to justify the additional cost of a more expensive detector in South Florida where you can hunt in the water more of the year and where there is a lot more expensive jewelry to be found.  The additional expense can often be paid off by a single find.

I mention the relative prominence of the Excalibur on the Treasure Coast as compared to the CTX in South Florida only to point out how situations affect detector selection.

The third detector that I want to discuss is the Garrett ATX.  The ATX is often used in the gold fields and has good sensitivity to small gold.  The cost of the Garrett ATX (just over $2000) is close to that of the Minelab CTX.

The ATX is very different from the Ace, the Excalibur and the CTX, which I just discussed in passing.

I've discussed the ATX some in recent posts.  The keep it short, the ATX is a not the easiest detector to use straight out of the box - at least not if you want to be absolutely sure that you are getting good performance from it.

The ATX is a Pulse Induction detector and is very sensitive to small iron.  If you are someone who likes using a lot of discrimination, the ATX is not for you. The Excalibur is not overly sensitive to iron, but the ATX is very sensitive to iron.  Yes the ATX offers discrimination, but if you use much of it, you will really reduce sensitivity to good low conductive targets and negate the very features you paid for.

The ATX has both a non-motion and motion mode.  The non-motion mode is the most sensitive, but also the most difficult to use.  Even the manual states that the non-motion mode is not for beginners.

To get near optimal performance out of an ATX requires experience and skill.  If you want maximum sensitivity and depth, which is considerable with the ATX, you need to get the settings right.

So when would you use the ATX on a beach or in the shallow water?  My answer is, When you want the best depth on small valuable targets and have the patience and skill to deal with junk.  

The ATX will detect near microscopic pieces of iron, but it also gives you good sensitivity to small gold.  It will detect a small gold ring deeper than it will detect a clad dime. You will get good depth on small gold IF you use the ATX well.

There are a lot of options and settings on the ATX.   Careful adjustment and proper use will pay off in good performance.

There are times when the ACE, costing around $250, would be the better choice than the ATX, which costs about ten times as much.  The ACE might well be the choice in dry sand when you want to quickly skim for modern finds, as one example.

This post is not about three or four detectors.  It is about making calculated strategic decisions based upon how features of different detectors match the circumstances and your goals.

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Odyssey Marine Explorations stock has really fallen off as they are being sued by the Securities and Exchange Commission. 

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On the Treasure Coast we have another couple of days of smooth surf and South winds.  Nothing new or exciting about that.

Happy hunting,
TreasureGuide@Comcast.net