Ancients and Medieval Coins are not in my comfort zone, I'm a collector of US Coinage. I have acquired two long cross pennies, One Henry III, the other Edward II. Both have been clipped. How does this affect their overall value? Is it comparable to a US Coin being cleaned? To give you an idea of severity, the Henry III piece should weigh about 1.6 grams; mine weighs 1.3 grams.
Hey, can you post an image? Is it just one part that is clipped, or is it a small layer around the edge?
It really depends on the coin, how scarce or common it is for example. A scarce coin that is clipped would lose less of its value than a common one. But they all lose some value. It also depends on the severity, but there really isn't any rule of thumb. About the only way to judge it would be to check the auction archives and compare clipped examples to complete coins.
King Edward II This is the King Edward II coin. It was clipped more drastically than the other. I'm guessing at a value reduction of 5 to 10% on the first coin and 15 to 20% on the second. I couldn't find comparable auction items at this time. Anyone have other thoughts?