■ I’ve read about patina on ancient bronze coins. Can the discoloration on U.S. copper coins be considered to be patina as well?
The short answer is yes. Patina will occur to a coin either naturally or by chemical manipulation. Basically, patina is oxidation. Patina will typically appear to give a green, blue, red, or light toning to the surface of a coin. The patina on U.S. copper half cents, cents, and 2-cent coins is typically described as Red, Red Brown, or Brown.
■ How much damage will a patina do to a U.S. cent?
Patina protects rather than damages the surface of a cent. Ironically, while an attractive patina often enhances the desirability of an ancient coin, patina is treated just the opposite of U.S. copper coins. A cent…