I say "possible" because this may already be common knowledge to the modeling and scenery community.
At the hardware store (Lowes) the other day I found these 12 x 12 panels made for kitchen tile and counter backsplash for about $10 each. They have a mesh paper backing that is easy to cut. Better still, individual stones are easy to peel off. These individual pieces can also be cut -- sort of. Take a piece and set it on a hard surface. Turn it over so the back surface is facing up, set a chisel in the middle and tap lightly with a hammer and they typically break into to two even pieces. Last photo is a wall section I created. I like it. To me, it's a good looking alternative to the molded pieces sold for O gauge.