I am posting here because I suspect it is an old US coin. Although it could be an old foreign coin. I don't know that is why I am asking for help. Had to take the picture on an angle to get any details. That pink thing is an eraser holding up the coin. Very smooth coin with smooth edge. Any guesses as to what it is?
Correct. An old George II copper. We'd need to know the diameter to determine if it's a farthing or a halfpenny.
I've collected British coins off and on for a quarter of a century and have dug both farthing and halfpenny coins of George II while detecting. If you metal detect colonial sites from the 1700s in the eastern USA, chances are, the most common colonial copper you'll find is a British George II halfpenny, while the most common silver coin you'll find is a Spanish Charles III Mexico City half-real piece.
28 mm means a halfpenny, then. Not surprising at all for a New Jersey find. Y'all have all kinds of interesting things sleeping in the soil up thataways. Including your own NJ coppers from a bit later in the 1700s, as you know.
