Replace blocks if they are in a certain biome.

all stone or just some

With a procedure you could do something like this, with either the on world created (or something, not on computer to look), or on world tick. For the procedure do

If biome is Your Biome

     If block at x y z = stone block

       Replace block at x y z with newstone block

The on created, or on loaded or whatever it is, will only replace them at the beginning, the on world tick will always replace them when you put it down, but might get laggy... So do the on created on..

did it work?????????