Can someone explain what's going on under & beside the date of this coin ?Do you think it's gas bubble's,a clash,or just PMD?
PMD - Post Mint Damage. I believe what they call Zinc Rot - when the zinc core starts to rot under the thin copper plating - on the Mint Mark. These new Cents aren't made like they used to be. I have pulled similar Cents such as yours out of the ground metal detecting.. with worse damage.
Yep, that's what "zinc rot" does--the metal oxidizes to a white powdery material, which takes more room and pushes up the plating.