Yes, each one was a full hunt from a different site.
I never really go out hunting for this much clad but I will happily dig it while waiting on the relics,older coins or silver and gold jewelry I usually look for.
The $200-$300 dollars in clad I found every year for several years does come in very handy when I need to buy a new detector or any accessories for this hobby.
Concrete has nothing to do with it, if modern clad coins are buried in the dirt unlike silver coins the outer coating reacts badly and just get really dirty to different levels depending on your dirt.
Wait until you dig up a few one cent coins minted from the middle of 1982 to present.
I don't call them pennies anymore because the U.S. never minted any coins that have the word penny on them and never will so everyone that uses that term is just...wrong.
Acid in the soil eats away at the zinc these coins are mostly made of so they don't just get ugly and dirty but the longer they are in the ground the less of these coins you are likely to find.
Not less coins, less OF the coins.
We all finds these wrecked up coins but I live in the south with a bazillion pine trees that put out tons of yellow pollen which settles in the ground, mixes with rainwater and sinks down into the soil and turns into zinc eating acid so I am doubly blessed when it comes to digging my share of these stinkin' zincolns.
View attachment 464758
Oh the other hand mostly copper coins like older wheat cents, Indian head cents and many others can turn from that new copper color into a beautiful green one with the prettiest patina you have ever seen over time.
We all love digging up these types so in some cases the dirt kills our coins but in others it makes them beautiful.
View attachment 464759View attachment 464760View attachment 464761
As I mentioned in my first post about not all silver coming out of the dirt clean and here is a good example of that in these before and after pics.
This silver ring was found in the bank of an old, forgotten fishing hole I found in the woods in a huge park one time, this ring and a blackened silver quarter I found at the same site were sitting in the moist dirt at the edge of the water for years and wet dirt plus silver plus time equals a sulfuric acid reaction that turns silver from shiny into this black color...another chemical reaction that you might want to know about in case you come across some out there in your travels.
I didn't clean this ring by buffing and polishing, that would have been impossible because of all the little nooks and crannies, but instead I used science...water, baking soda, aluminum foil and a little heat.
A chemical reaction tarnished my silver so I used another chemical reaction to easily clean it up.
View attachment 464763View attachment 464764
Bet you never thought your knowledge about metallurgy and chemistry would grow when you decided to get into this hobby, did you?
Your quarter is probably in better shape than you think, once cleaned they look different so after you gather enough of them and want some advice on how to clean them most efficiently so you can go out and spend it all without getting some dirty looks or killing innocent Coinstar machines, which I have done, just search the forum for the chemical, hand and mechanical methods we use to clean our dirty clad coins to turn them spendable again.