I'm not sure if I'm seeing this correctly, but it sure looks like a piece of polyurethane coated slate on the floor, in front of your zero clearance fireplace. If so, relax, this won't be too hard. The first task is to feather the edges of the damaged area. You might want to do this with 3/0 or 4/0 steel wool. Just sand enough to blend the edges in, around the damaged area. Now vacuum the area and give it a quick wipe with a tack cloth. The next step is to lightly brush a coat of water based polyurethane into the damaged section. It really doesn't matter what finish is down now, water based poly will typically be compatible with most existing finishes. Give the area a few coats and see how you did? If it still is noticeable, don't sweat. Take the 4/0 steel wool, and give the whole area a good rub down. How does it look now? It may be just fine. If not, recoat the whole area with poly, and you should be good. Easy fix. A good paint store will have the advice and all the stuff, and water based poly is pretty harmless and easy to use. Good luck.