The effects of farm chemicals.....

[Digger]

Yesterday, I dug a few coins from the site of an old picnic area. The site was used in the late 1800's, into the teens. For the past 90 years it has been a farm field. Mostly corn and soy bean rotation. None of the coins are anything special, other than to show the comparison of how different metals react to "soil conditions". The two cents toward the top of the photo are early Lincolns. The two at the bottom are IH cents. The nickel is a Buffalo and the dime is a Barber. Over the past 35 years, I've noticed most Buffalo nickels come out with the orange tint to them. Whereas Shield nickels and V nickels have a deeper red color. The copper pennies in this field were particularly nasty. Highly corroded and pitted. I suspect that is due to the chemicals put on this particular piece of ground as other coins found in the vicinity did not look this bad. But, as always, silver comes out looking bright and shiny. None of the coins have been cleaned. I carry a small plastic bottle of water with me detecting and place coins in the bottle as I dig them. It ususally makes the dirt easier to wipe off. But I don't think there is any hope for the coppers found yesterday. HH Randy

 

[NH Bob]

Hi Digger,
My post above is a good example of what you're talking about. Any longer and that coin might not be IDable. You can see that the coin was laying with the reverse up. I might add that in the east here we also deal with acid rain.

 

[B.T]

G,day Randy. Dont you just hate it when you find a good hunting site thats had a squillion gallons of chemicals poured over it. I found a good one over here where there were coins and relics everywhere but most of the coppers had had their day and were mostly worthless apart from historical sort of significance. I have found too over here that I get better coins out of sheep farming land as opposed to cattle farms. I guess that its because the cows expell a gal at a time when they go and it soaks in more? Maybe they too have a different chemical makeup in theirs? Who knows? I reckon they get knocked around more in cattle farms also as when it gets really wet and muddy the cattle being heavier tend to sink down deeper than sheep do as they walk and cause the coins to abrase on the gravels. A lot of our topsoil here in central vic is only inches deep. But sheeps farms is the way to go.
Have a good one.

 

[Jackpine Savage]

Digger have you ever tried hydrogen peroxide for cleaning those pennies?
If they are badly corroded it won't help much if any but it will take off the looser surface crud without damaging the coin.

I use a small juice glass and nuke the peroxide for about 30 seconds then drop the coin in.... plop plop fizz fizz

Tom

 

[NH Bob]

It wrecks mine.
Example the coin I dug the other day was a 1818 and looked like the green one until I used Peroxide and the 1810 with the hole is the result. Use caution if you want to keep a date.
[attachment 54317 DUPS640.jpg]
[attachment 54319 gt.JPG]

 

[oldcellar]

The farm chemicals do not have anything to do with the way that coin has "pitted". The soil pH is the culperit. Soils vary tremendously from one square yard to the next. They may look the same but, the acid levels can be dramatically different. Not to mention the soil's CEC (Cation Exchange Capacity)and salt index. There are so many variables that one can only guess most of the time.

 

[Jackpine Savage]

Bob,

The coins around here have not been in the ground as long as yours. I have yet to have an IH ruined by peroxide. I only leave them in long enough to get off the surface dirt and crud. Diggers idea of putting them in a small bottle of water is the best way to keep the soil from hardening up on a coin after they are dug.

Tom

 

[Digger]

I disagree with your statement that farm chemicals do not have anything to do with the way that coin has "pitted". Anhydrous ammonia, a very common fertilizer used around these parts, is especially corrosive to copper alloys. I have posted that info under my initial post.

HH Randy

 

[Digger]

More than 80% of the ammonia produced in the United States is used for agricultural purposes. Anhydrous ammonia is commonly used nitrogen fertilizer (82-0-0). The common metals are not affected by dry ammonia. Moist ammonia will not corrode iron or steel, but will react rapidly with copper, brass, zinc and many alloys, especially those containing copper.

 

[NH Bob]

That's why urine is good for making new copper look old when you work with copper flashing around a chimney or valley.