Monday, September 23, 2013

9/23/13 Report - Why Do The Two Sides of One Coin Sometimes Corrode So Differently? Florida State Parks & More

Written by the TreasureGuide for the exclusive use of

Big One Penny

I dug this big Queen Elizabeth penny the other day.  It isn't old, only 1967, which is only four years off of what the state considers to be a historic artifact, as simple as that might sound.  It isn't valuable by any sense of the imagination.  In the online references it is listed as bronze.

When I first dug it up I thought it was a half dollar.  I couldn't see the other side at all and didn't take the time to really look at it very good.  I just tucked it away thinking it was probably a half dollar.

The reason I mention it is because the two sides of the penny were very different.  I'm not talking about design but the patina and corrosion.

The side you see in the photo is basically how it looked when it was dug.  The opposite side though, was covered with a thick green crust that obscured all of the coin.

Why would two sides of the same coin look so different?   That was my question.

I've seen a similar thing happen before.  I saw it on a half reale that was dug down at Jupiter some years ago.

That half reale is shown below.

Dug Half Reale With Sand/Shell Crust

Different metals corrode differently and you can often tell something of the composition of the coin by how it corrodes.  Copper and bronze will often have some green on them, like the penny above had.

This half reale though just had a crust of sand and shell on one side and the typical black appearance of a sea seasoned cob on the other. 

When the cob was dug I could easily see the cross etc. on the other side.

You can see the other side pretty much as it was dug below.  There is some crust on the other side, but very little as compared to the side shown above.

Other Side of Same Half Reale
It is possible that the heavy crust only accumulated on one side and not the other.  Or I guess it is possible that there was a heavy crust on both sides but the crust on one side was worn off after the cob got uncovered.

I think the first theory is most likely.  I think that the very heavy crust was formed on one side maybe because of how the cob was positioned for all those years.

The heavy crust turned out to be a benefit because it kept the detail of the cob from being worn down.

See photo below showing detail revealed when the heavy crust was removed by acid.

Like I said, the bronze penny also had two very different sides.  The one side had a heavy green crust while the other side is as shown above.

Unfortunately  I didn't think to take a photo of the green crust before I removed it.

Same Half Reale Showing Detail Preserved by Crust.
Another possibility besides one side reacting differently because of its buried position, or the surface being cleaned by movement of sand and water after being eroded out of the bank, is that the coin or cob could have been buried next to something that protected it either physically or electrogalvanically.

What is your idea?

Here is a photo of the half reale showing the side that was heavily encrusted after the crust was removed.  Notice how well the heavy crust protected the cobs surface and preserved the detail.


I believe that the cobs that were recently found and shown in this blog were actually pushed up onto the beach weeks ago, not recently.  From the circumstances, William thinks that might well be right.

I also felt that was true of some of my recent finds.  

If you hunt the over hunted places, you won't find things like that, but they can remain for a long time after washing up in locations that are less frequently hunted.


I just just read yesterday somewhere that Sebastian Inlet State Park is the second most visited state park in Florida.  That is quite a distinction.   The McClarty Museum is part of that.

 Right off I don't know which is first most visited.

Here is a link that will introduce you to all of Florida's State parks.

Which have you been to?

An Audubon Society report said the following.   Florida’s park visitors provide a critical economic boost in the communities where they are located – and that’s more important now than ever. For every 1,000 people attending a state park, the total direct impact on the local community is more than $43,000, a 2008 DEP study found. 

Trying to find out which was the most visisted, I found a 2012 listing in HolidayTripper that didn't have the same order.  Here is what they had.

The most visited state parks in order are:
  • Honeymoon Island State Park, Dunedin
  • Gasparilla Island State Park, Boca Grande
  • St. Andrews State Park, Panama City Beach
  • Lovers Key State Park, Fort Myers Beach
  • John Pennekamp Coral Reef State Park, Key Largo
  • Anastasia State Park, St. Augustine
  • Bill Baggs Cape Florida State Park, Key Biscayne
  • Sebastian Inlet State Park, Melbourne Beach
  • Stump Pass Beach State Park, Englewood
  • Bahia Honda State Park, Big Pine Key

After researching some more I found that Honeymoon Island consistently shows up as number one.  I've seen different things for Sebastian Inlet, but is always listed among the top few.

How many of those have you detected?  I can only list three.  There is one on there that I detected many more times than Sebastian.  I've mentioned it in past posts.

Low tide on the Treasure Coast will be around 5:30 PM today.

We'll be having a 1 - 2 foot surf for a few days.

Happy hunting,