This site is dead so here goes...

Ism

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Jun 17, 2009
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Michigan
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Primary Interest:
All Treasure Hunting
I hunt mostly sports fields during the summer months when farm fields are off limits. I'm very careful not to damage the turf and one can hardly tell I was even cutting plugs.
In sports fields I don't go deep, 4-5 inches is my max as I'm looking for jewelry and coins.

At any rate... My comment is an observation I have from digging hundreds of zinc pennies at these sites (small 925 silver jewelry has a VDI in the same range).

I live in Michigan, so this probably doesn't pertain to some areas of the country like TX, FL, AZ, etc. but I've noticed that almost always the zinc penny will be surrounded by a cluster of dirt and fine roots that I have to break apart to reveal the penny. At first, I thought the zinc was acting like a nutrient for the grass roots, but now I'm leaning towards the soil treating it as a foreign body and creates an abscess around it.

Has anybody else noticed this and what do you think about my hypothesis?
 

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I hunt mostly sports fields during the summer months when farm fields are off limits. I'm very careful not to damage the turf and one can hardly tell I was even cutting plugs.
In sports fields I don't go deep, 4-5 inches is my max as I'm looking for jewelry and coins.

At any rate... My comment is an observation I have from digging hundreds of zinc pennies at these sites (small 925 silver jewelry has a VDI in the same range).

I live in Michigan, so this probably doesn't pertain to some areas of the country like TX, FL, AZ, etc. but I've noticed that almost always the zinc penny will be surrounded by a cluster of dirt and fine roots that I have to break apart to reveal the penny. At first, I thought the zinc was acting like a nutrient for the grass roots, but now I'm leaning towards the soil treating it as a foreign body and creates an abscess around it.

Has anybody else noticed this and what do you think about my hypothesis?
Zinc is used in fertilizer, dirt doesn't know a pebble from a penny.
 

Zinc is used in fertilizer, dirt doesn't know a pebble from a penny.
Zinc is used in fertilizer but so is copper and iron. I never see the same when digging a copper penny or occasional iron target. Nor have I seen it in the occasional zinc plated hardware I've dug.
 

A lot of the zinc pennies i dig are partly ate away . They just do not seem to like being in the ground
 

A lot of the zinc pennies i dig are partly ate away . They just do not seem to like being in the ground
Yes, and there's a reason for that. Just not going to point it out so quickly (hoping someone else will contribute to this thought exercise), but it is the reason I theorize that the roots are bundled around the pennies. They are even attached to the pennies in many cases covering it in a crisscross pattern.

However, I'm not so sure the reason why. Is it's because they are attracted to a nutrition source or an attempt to contain an irritant. I have no idea what happens underground with roots, but trees and plant tissue will build up around an irritant and make a knot similar to a living tissue with an abscess.

Maybe abscess is the wrong word, but it's the only one I can think of that describes what I'm trying to convey.
 

Zinc is a very reactive metal. When exposed to the atmosphere, it quickly forms an oxide layer that protects the zinc beneath from corrosion. That is the basis of zinc plating (galvanizing) of roofs, nails and other fasteners to be used outside. However, when the oxide surface is breached, the metal underneath reacts quickly. In the ground, I suspect that the moisture and dissolved salts in the soil are able to continuously breach the protective layer, corroding the zinc beneath and eventually destroying the coin.
As to the root mass adhering to such coins, the soil immediately surrounding the coin would have a high concentration of zinc salts. As others have speculated, that might attract roots. Zinc is one of the trace elements needed for plant growth.
 

I hunt mostly sports fields during the summer months when farm fields are off limits. I'm very careful not to damage the turf and one can hardly tell I was even cutting plugs.
In sports fields I don't go deep, 4-5 inches is my max as I'm looking for jewelry and coins.

At any rate... My comment is an observation I have from digging hundreds of zinc pennies at these sites (small 925 silver jewelry has a VDI in the same range).

I live in Michigan, so this probably doesn't pertain to some areas of the country like TX, FL, AZ, etc. but I've noticed that almost always the zinc penny will be surrounded by a cluster of dirt and fine roots that I have to break apart to reveal the penny. At first, I thought the zinc was acting like a nutrient for the grass roots, but now I'm leaning towards the soil treating it as a foreign body and creates an abscess around it.

Has anybody else noticed this and what do you think about my hypothesis?
Yea it is pretty quiet on this site. I spend most of my hunting time out in wooded areas looking for remnants of homesteads from around 18 century preferably. I have not made any substantial finds YET But I keep at it. I love the woods I find just walking in the woods satisfying regardless if I find anything or not. I look for rocks and boulders that stand out, Old trees that may in some way be marked. Even mounds of dirt that do not match the landscape. caves etc.. I live in Wilson, North Carolina
 

I hunt mostly sports fields during the summer months when farm fields are off limits. I'm very careful not to damage the turf and one can hardly tell I was even cutting plugs.
In sports fields I don't go deep, 4-5 inches is my max as I'm looking for jewelry and coins.

At any rate... My comment is an observation I have from digging hundreds of zinc pennies at these sites (small 925 silver jewelry has a VDI in the same range).

I live in Michigan, so this probably doesn't pertain to some areas of the country like TX, FL, AZ, etc. but I've noticed that almost always the zinc penny will be surrounded by a cluster of dirt and fine roots that I have to break apart to reveal the penny. At first, I thought the zinc was acting like a nutrient for the grass roots, but now I'm leaning towards the soil treating it as a foreign body and creates an abscess around it.

Has anybody else noticed this and what do you think about my hypothesis?
From digging things for 5+decades.
4 of those were mostly basically urban environments.
I've seen the little clumps of roots around the coins.

Now it really depends on the site.

Grass that has a thick grass over mineral soil where the coin stays within 4" of the surface the coin will be in a clump sometimes.
If the coin is below the sod level it may have traces of organic material(grass) on the bottom side even.
Most of the time the coin will displace from the soil, leaving an impression.

Think of it this way.
The coin is lost, trampled on for years. The grass is mowed 100s of times leaving more dead material on top of coin. (Build up of organics)

So now the coin is in roots of the grass and the roots can't go through the coin, but they grow around the coin.
Capturing it in these little clods that we find.
The best part is breaking them apart to reveal the treasure. 😁
 

The main reason the coins are bubbled and eaten away after they've been in the ground for a while is due to galvanic corrosion between the copper and the zinc. Yes, maybe the roots are attracted to the metal salts given off by the rotting penny, but the areas I find the root bundles are fertilized on a regular basis. Ironically, in unfertilized areas, I don't encounter the root bundles as much.
 

The main reason the coins are bubbled and eaten away after they've been in the ground for a while is due to galvanic corrosion between the copper and the zinc. Yes, maybe the roots are attracted to the metal salts given off by the rotting penny, but the areas I find the root bundles are fertilized on a regular basis. Ironically, in unfertilized areas, I don't encounter the root bundles as much.
Maybe you can post some pics?
 

Maybe you can post some pics?
I have one of an uncleaned penny covered in root prints. I should have taken a couple of the pennies in root balls yesterday. I had my phone on me while hunting which is rare. I plan to go tomorrow so I will be mindful to grab a photo or 2 and maybe a short video.
 

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I have one of an uncleaned penny covered in root prints. I should have taken a couple of the pennies in root balls yesterday. I had my phone on me while hunting which is rare. I plan to go tomorrow so I will be mindful to grab a photo or 2 and maybe a short video.
can you make out any dates or anything on it
 

can you make out any dates or anything on it
It's a zinc penny. Could be anything after 1981. I don't concern myself with cleaning them.
It's just an example how the roots attach themselves to the penny.

UPDATE: I was able to edit this post so here's an example of how the pennies come out of the ground at a soccer park. The dirt clod is held together by a network of fine roots. The more corroded the penny, the denser the root network seems to be around the coin. This coin was pulled from about 4" down. I might have upset some people with my thread title, but it wasn't intended in that way.
 

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Down here in AZ, the zinc pennies just come out with high corrosion of the zinc - much like a zit that has been popped. I just throw them away in the trash after I find them. Today, I found 3 and yesterday I found 12 - different parks.
 

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