I have a concrete hearth- left over from a fireplace that is now gone -enclosed in the wall by the former owners of the house back in the 70’s. Opening the wall is not an option, the flooring is refinished oak – how can blend this concrete in and incorporate it with my now beautiful old oak refinished floors? This slab had been hidden by the old carpet.
The concrete hearth is probably around 4″ thick. The only option I can think of is to remove the hearth and install oak flooring. A good hardwood flooring company can lace in the floor. If you are refinishing the entire floor, the new flooring should blend in very nicely.
I think anything else you try, will look like an out of place patch.