The photos may not show the bronze color as I see it, but the coin on the left has a bronze or light gold color. I did soak it in acetone to see if it might be paint, but it stayed the same color. Both coins weigh the same... 2.5 Is this a lack of copper on the coin?
If it was bronze it would weigh in at 3.1 grams. Zinc cents are as I recall 2.7 grams. Either way not the 95% copper 5% zinc of earlier years.
Copper plated zinc are 2.5 grams. A gold color can come from the plating solution being used to long and becoming contaminated with excess zinc. As the zinc concentration rises the plating has more and more zinc in it and takes on a yellow brass color. I don't consider these off color cents to be errors because EVERY cent will have a slightly different amount of zinc in the plating. At what point do you decide "This is too much zinc so these are errors."? You would have to have an XRF gun to tell what the exact composition of the plating is (can't accurately measure it by eye.)
