This was my favorite coin from a lot I purchased from @physics-fan3.14, and I wanted to share it specifically and see what folks think she grades. I have always been a fan of black. Black firearms, black knives, black leather jackets, etc. Mercs are no exception, and I just recently started to actively pursue Mercury Dimes with dark and black toning, but they can be elusive, especially with an even and non-splotchy appearance. Some of you may call me crazy, some may find black coins ugly, but there is something incredibly sexy to me about a coin with a thick, dark, original skin. Just look at this:
I agree with the EF grade. These black coins can sometimes be attractive if there is enough luster left underneath. When the black becomes dull, then it has progressed to the point of damage. As I recall, that one wasn't completely black but had some bluish undertones, and decent luster remained.
This happens due to a higher temperature setting during the annealing process and if it 8s a black beauty, it will retain 100 percent of 5he mint luster. If ANY luster is affected, it's a foreign substance and would be considered pmd. Their are lots of other luster compound issues possible as well. I collect luster compound error coins. They take 40 or 50 years to oxidize through much thicker luster layers but are also some of the highest recorded tones coin sales you'll ever see. I have 2 of these btw. Let people say environmental damage and you can steal wm all day for melt value. It's always nice o see people assuming at there own cost and your own savings. Great find. I'd almost guarantee it is an annealing error. Shows all signs. I'd ask at least 500 out of it and could bring significantly more at auction.