What is the best media on which to mount a normal size baseless stone?
Something extremely hard like tempered glass, ceramic tile, etc. or something with a little "give" like thick rubber or conveyor belting.
How about an 8 by 3 piece of ceramic tile glued to a 1/2" thick piece of conveyor belting then glued to the stone?
(Obviously I have access to a ton of free ceramic tile and conveyor belting.)