People sometimes ask us if you can install the Hovr on a stone wall. The answer is, yes, in some cases. However there are definitely some considerations and adjustments that must be made. Also note that we don't typically recommend this with the aluminum bracket, as the standard screw size we use with this bracket means the screws / attachment points tend to be too weak (#16 pan head wood screws max), especially when the wall is rough or jagged as it often is on stone. For the steel bracket on the other hand, used for mainly mantels (most fireplaces are brick), this is no problem. Even for outdoor BBQ's etc, this is viable, but again this is mainly a job for the steel bracket.
First, a stone wall is typically very uneven / irregular (some more than others). Scribing a shelf to match this is an unrealistic solution. What this means is that the best bet here is to add a wooden spacer or buffer between the wall and the back of the male bracket, to act as the eventual connection point between your stone and shelf at (this should be at least as long as the male bracket), as far as the furthest protruding stone / wall point.
See the below examples for more information:
The below brick diagrams also apply to the stone concept: