This is called a Non Mint Error. Somehow the high areas of your Copper Plated Zinc Cent was worn off. Then the Zinc was exposed.
First, welcome to the neighborhood @Alexamonkey ! Sometimes, extreme close-ups like yours can confuse the issue, and it is better to back off a bit so we can see the whole coin in one image. However, what @paddyman98 said was correct.....PMD! Chris
