Here’s a better photo

It appears to be stone not tile, marble or granite? What color would you paint it? I can't imagine it would make it anymore beautiful than it is.

Yes I'm not sure what it is. To me it is just a huge eyesore in the middle of the room but it's nice to get a different perspective. Some suggested pulling in the black in some accents around this room and I was thinking of trying this rug.

I think the fireplace is a statement. Unfortunately it is right there, in your face. Instead of painting the entire wall black, what if you wallpapered the wall around it?

There are so many great wallpapers. If you are hesitant, try a peel and stick. It need not be a solid black.