surface slate/grassy slate blocks

I don't really care what it's used for (my suggestions are to put is in between dirt and stone in certain biomes and add a few biomes where there's a lot of slate) but I want a non-deep variant of slate in the game, it could be light brown in color and be similar to deep slate in appearance and have similar variations, but it would also have to look slightly different. Slate block could grow grass on the top much like dirt, accept that grass would also change the side textures to have grass growing out of them, and it could react to moss much like how grass reacts to snow with a special texture variation. I just think it would be neat to have another stone-esque building material in the game.