Im sure Ive had this coin up before after a second look the 1985 Lincoln penny has multiple spots / circles what are these and how are they caused during the minting process ? Apologies iphone pics and a cheap usb microscope Thanks in advance
It took a decade or longer for contractors to produce some decent copper-plated zinc blanks. The Mint used both good and bad and fed them into the upsetting mills to create planchets ready for striking. What resulted was untold millions of crappy Zincolns with surface anomalies such as plating blisters, and when struck, also split-plate doubling. As soon as the blister pops or the surface gets exposed/scratched, zinc rot begins. Take a picture of the penny as a memento, ‘cause it won’t be around much longer.