Want to share a recent purchase. It is a quite interesting state quarter error. The error is an "obverse struck through clad layer". Instead of striking on a blank causing an indent, this Connecticut state quarter is struck on a detached clad layer (from another quarter I believe), leaving a somewhere blurry image on the obverse side. I like this quarter, since the "struck through" is positioned pretty nicely, covering Washington's face. It is a great "companion coin" to my other struck through clad layer Susan B Anthony $1. Please post if you have a similar "struck through clad layer" error coin.
What is interesting is that the size of the clad strikethrough on both coins are nearly the same size. Chris
My first reaction is that these must be super-rare, since you have to first get a clad layer to detach, then strike another coin through it. But if a clad layer does detach during striking, I guess it's pretty likely to get stuck, being so thin. I have no idea how often clad layers are lost during strike, as opposed to falling off the blank long before it makes it to the press. I'd think the upsetting step would knock most of them off, if they didn't fall off while being punched from the stock...? Edit: This is why I keep coming back to the Errors forum. I don't collect them, and I have no interest in microscopic varieties or errors -- but thinking about how an error happened helps me better understand the coin production process. And I like understanding how things work.
Most missing outer clad layer coins are from planchets that lost the outer layer before the planchet was struck as a coin. We don't know when that outer clad un-struck layer was detached from the blank/planchet, but it (the layer) could have easily been in the bins that feed the planchets into the coining, and was fed into the collar - due to it being lighter, it wouldn't necessarily fit perfectly into the collar like a full planchet, thereby laying only partially into the collar when struck, like the two nice examples shown.
Very nice, though the TPG should have put the more interesting error side towards the front of the slab.