That will really depend on how flat the stone is. Generally we don't mount over stone as it tends to have too much variation in depth, and our product can not be easily coped to fit. We are usually mounting on drywall or osb. If your stone is really flat, it may be possible, but our mantels need to be glued and screwed to the wall, which could possibly present some problems. The mantel needs to be screwed into the stud of the wall, so you would have to drill a pilot hole through your stone as well in order to mount it. The construction adhesive and caulking we usually use could have a hard time sticking to stone if it is very smooth.