Mr Fidgit said:stonecunning is a hard ability to replace. i don't think you could just change the substance to make it work. (woodcunning, treecunning, tobaccocunning) i'm not sure what a good ability would be to replace it. the choice of any feat would be too powerful, but a specific feat (or an ability that emulates a feat) may not be. (example: halflings have +1 to all saves, which is exactly what Luck of Heroes gives)