This is a strange looking mint mark situation. I see no damage near the mint mark, nor do I see any bubbling on the coin. Ideas any one ?
Hi Welcome to CT. It looks like die deterioration. Part of the D looks like it slid off. But you should wait for one of the experts to comment.
ttp://www.lincolncentresource.com/FAQ/errors_vs_varieties.html A little reading for you until the experts show up. https://errorvariety.com/OFD/PSD
It is a plating blister and the underlying zinc is pushing it's way out. Damaged, sorry to say. We call this zinc rot.