This mod is in a quite functional state, but not a polished state. It currently features 18 stone types that all spawn in the world, cobble for most of them, and bricks, cracked brick, and blocks for all stone types. If your game supplies stairs, you will have access to stairs and slabs. If your game has walls, then you will also get walls for most stone types. The placement of the stones in the mapgen is nearing finalization. More stones may be added, and you can put a feature request on ContentDB or the repo for new ones. I probably won't add any boring stones though.